British Expats - Lots of different work exp but no relavent quals

Hi everybody this is my first post :) so be gentle with me.
I'm desperate to emigrate to NZ with my family as we already spent a year there on a working holiday and loved it. My problem is that as the main applicant I'm short of points without a job offer.
I've a degree in Chemistry but i've never done any work related to it. I've been mechanicing (spelling??) on cars and motorbikes (no qualifications in either) since I was 12 but other than a 2 year stint in a bike dealership its all been either for family business's or myself.
I've been doing sign making for about 4 years now including about 2 years on the job training with a company that has now closed down, no formal qualifications in it other than an ABC certicate in screen printing but I don't think its worth any points.
Currently seem to have 100 points for EOI if I can use the 50 for my degree and then 15 points from 4 years exp signmaking (don't know quite how i would prove this though)

Am looking long term so I was thinking about getting either a qualification in motor vehicle mechanics so I can claim for that work exp and hopefully get a job doing it in NZ or one in the construction trades (preferably joiner) on the long term list then work here in the UK to get experiance as I can turn my hand to most other things. But does anybody know what current city and guilds are equivalent to the NZ level 4 qualifications everything seems to need.

Alternatively does anybody reading this need a sign maker in NZ???
Cheers
Giles