This article is from the Apple II Csa2 FAQ, by Jeff Hurlburt with numerous contributions by others.
Prototyping boards certainly would be the same for the II, II+, IIe, and IIgs. The slots on all slotted Apple IIs are physically identical There are minor differences between the slot signals on the various machines and on some slots in the same machine, mostly affecting rarely used special pins. (See Question 004 for more details on signal differences.) By: David Empson