da9000 @ I ran my A3000UX with one for around 6 months before I was able to get my hands on the right chip, having said that I can't confirm if that is true for all A3000 rev boards but it was for both my Rev 9/03 & Rev 9/02 machines.. I don't intend on spreading mis-information but I simply report what I have observed.
Some of the earlier A500+ machines actually used the 8375 318069-XX 2Mb Agnuses as found in the A3000T. However the majority of A500+s used the 390544-xx variant.
Commodore did a lot of strange things.