The working machines all come up with a picture of a hand holding a disk with the number 1.3 undeneath - I assume it's asking for Workbench 1.3. One of the machines displays 1.2 instead of 1.3.
The infamous disk in hand indicates the version of the kickstart installed on the computer. The kickstart is the Amiga's internal operating system. The workbench simply provides a GUI for the user, as the ROM is too small to hold it.
There's also two of those internal expansion boxes that live under the rectangular cover on the bottom of the machine - I think they're probably RAM expansions
Bingo...
So, here I am, surrounded by Amigas and I don't know what to do with them. Any ideas?
Keep one or two for yourself, sell the working ones on eBay. You can also chop up the non-working ones and harvest the parts and sell those on eBay also.