I was not aware of what you mentioned in regards to the early and late serial number boards -
I am not a particular Apple fan, but I used to come across AEK2s fairly often in the second-hand/junk market (but no longer). I compared new finds to what I had and upgraded until I ended up with a really nice one. I did not study the minutiae very closely, but I do know that I never got a salmon one, and that those 2 whites were late in the game (both date-wise and my acquisition of them).
The M0115 is much more appealing to me, and I went through several before I got a good one. I upgraded similarly so that I now I have a really nice AEK (orange) and AEK2 (cream) boxed up and stored away with ADB cable and iMate, for the day I get interested again.
Until a year or so ago, I did not pay attention to serial numbers of orange vs salmon, but I think that all of them that I remember had serial numbers between 200K and 900K. It is my understanding that orange is early and salmon is later, with no substantive difference between them.