Hello Immigration Gurus, Please help.

Recently I transferred my H1 from Company A to B. I have two questions.

1. Can I use my new H1 approval notice (company B) and old H1 visa stamp (company A) to leave USA and re-enter.
2. Recently I renewed my passport. My H1 stamp is in the old passport (which was stamped as cancelled and returned to me along with the new passport by the embassy). Will H1 stamp be still valid (if in case it can be used with new approval notice to re-enter) ?

Thanks