@giantweta
If you're having trouble identifying the A500 trapdoor expansions, you could try comparing them to the pictures on
http://www.amiga-hardware.comClick on "RAM expansions" on the left side. In future, you'll be able to go to "Browse by connection", and then select "Trapdoor (A500/+)", but for now that only shows up a tiny percentage of the cards produced for that trapdoor slot.