Can poly resin be used over west system epoxy?

[RoomToMove]

I just acquired a 1970/71 20sf from my friend! My brother and I are going to begin the rebuild process and it is our first time with any major fiberglass project. We are trying to decide on what resin to use. Looking for any suggestions. We were ready to buy poly however i was told the transom has already been re-cored with marine ply and WEST SYSTEM EPOXY....

Now, my understanding is that you can use epoxy over poly and vinyl but can NEVER use poly and vinyl over epoxy...

Should we continue and use west system for the entire project or do we have any other options?

Sounds like we might not have a choice...Thanks for your help.