Hi, in case ET isn't around to answer, the "Taxe de Succession" that must be paid on an inheritance, is levied on French property, cash, assets, etc... and payable to the French Government, wherever the named heirs live. (If your uncle specified in his Will that UK law must prevail, his property, etc... outside of France isn't concerned by French Inheritance Law, only French property).
In my (limited) experience, the Notaire deducts what's due to the Tax Office from the value of the bequests and the heirs receive the net amounts.
The Sales Tax is nothing to do with Inheritance Tax and it's the buyer who pays this, not the vendor.
Hope this clarifies a little! If you can't get hold of the Notaire's details and contact him/her to give your details "in case you're named in the Will and aren't sure that your uncle gave the current address" (a reasonable pretext for writing), you can only play the waiting game. My former neighbour's UK heirs had to wait nearly 4 months for the Succession to be completed and hers was straightforward....

I think dmu's answered it pretty much. All fixed assets in France, ie houses, come under French succession law regardless of where the deceased or the heirs live, likewise any cash in a French bank account belonging to a French resident.
To clarify about the property though - if you inherit property, inheritance tax is payable on the value of the property, as per the usual rules (ie if the property is valued at 10k you as a nephew would have to pay around 1k inheritance tax). This can be a problem if you want to sell, because property in France can take a long time to sell and the inheritance tax has to be paid within a fairly short timescale (not sure if it's 6 months or a year). So being left property/a share in a property, but no cash to pay the tax with, can be a very mixed blessing. If it comes to it you can ask to pay the tax in instalments or delay payment, but you would be charged interest.

Absolutely scandalous, is what my reaction is here. I would not have the ability to pay tax on property , let alone , in instalments .

This is legal robbery. Makes you wonder why some individuals (presumably) , try to evade or set up other , so called ´companies´ in tax havens to try and lessen the blow of Government greed.

This post has been an eye opener for me.

Many, many thanks again for this invaluable information.

In France, it is not just the super wealthy who pay but ordinary citizens who cannot set up offshore accounts or use tax havens.
If and when you have some figures and if you are unable to pay any tax due then you can give up your right to the inheritance.
Remember, if you inherit €10k and are required to pay €1k then your gain is €9k.
In France, you have to declare your world-wide assets in your tax return.
Hope it all works our for you.

It's a question of months. My above-mentioned former neighbour, before she died, inherited her companion's house and money. She had the choice of accepting to pay the 60% Taxe de Succession (as an unrelated heir) or waiving the inheritance. She chose to take the risk of not selling the house before the deadline for the Tax and by miracle she did manage to sell it. As a widow on a tiny Pension, she would have been in a real pickle had a buyer not come along at the right time, as the money that she inherited wasn't enough to pay the Tax.
@ the OP: I did say that things are different in France!
It's worth mentioning here that this Inheritance Tax is an incentive for "partners" to get married or "pacséd" (civil union), to avoid this horrendous percentage for the surviving partner.

The thing is that the ethos in France is for inheritance to pass down the family in a direct line - the 'Napoleonic code'. If you inherit from your parents I believe you have a tax free allowance of 100,000€ from each parent, after which the tax starts at a very low rate. So sons and daughters who get a substantial inheritance can pay significantly less tax in France than in for instance the UK. It's when the heirs are outside the direct line or even worse, no relation at all, that the tax is high. For non relatives (including an unofficial partner that you live with - so if your uncle and his partner weren't legally joined, your aunt could be in for a big shock) I think it's 60 per cent tax with a tax free allowance of 2,000 or so. So in practice, the French rarely bequeath much to non-relatives. To the French this is all quite normal, they're used to the concept that you leave your possessions to your children, and in fact probably not a lot of succession tax is paid overall. It's only if you're used to a different system where you have more freedom over who you leave things to, that it comes as a shock.
Another side of the coin of course is that in France, children are legally responsible for looking after their parents in their old age - if the parents can't afford to pay for their own care, the bills are automatically sent to the kids, and they have to pay even if it means tightening their own belts. It wouldn't be very fair if after paying the old folks' care bills, the sons and daughters discovered the house had been left to a favourite niece or nephew who hadn't paid a penny towards the care bills and they got naff all.
It's a different culture, historically the family bloodline has been very very important and the laws still reflect that, and in a way keep the tradition alive; couples who live together either get married or pacs'd, kids and parents look after each other, etc.

posts crossed, and yours is much more complete!
I hope the OP's uncle was advised by a Notaire as to the best way of protecting his "wife" if they werent married or pacséd, but that's hardly his concern.
P.S. Are you sure about a nephew's percentage? I found that brothers and sisters have to pay either 35 or 45%, which means that a nephew would have to pay 55%....

P.S. to #16
My neighbour's children didn't have any Taxe de Succession to pay, since the value of her property was less than their combined direct descendants' allowances, and the Notaire deducted his fees from her Bank Balance before releasing her money.
Another general point which occurred to me: a deceased person's bank accounts are frozen, so it's highly recommended for a couple to have a joint account with either signature valid, otherwise the surviving spouse will have problems for day-to-day living.

Me again, you're right with your calculation. I forgot about the allowance...