Highflyer
Technically you are correct that your 75/76 rating is the same thing but you will still have to complete a differences course which is usually one day in the classroom then a sim session. Your OPC/LPC will then alternate from the 75 sim to 76 sim providing you fly both types. (Well in the UK anyway)
I was offered the 75 at LBA (I still fly the 76 and have ETOP's experience.) but turned it down because the money was so bad. I have a summer contract lined up elsewhere but if i hadn't i would have accepted it.
HFS