The "label color" question is sticky. If I remember correctly, the oval beige plastic label with black printing is called "white", "beige", "gray", and "black" almost randomly and interchangeably.
There is also an actual black label that is used only on industrials, and they should be mentioned somewhere.
It seems that different plants changed components (eg lighter plates, barrel inserts instead of wire stabilizers, label color) at wildly different dates, so it is not true to say that a 1988 is "old-school" and a 1989 is not, or that a 1993 is sure to be a blue label.
I would also recommend that you discuss the cables, and the fact that the original black coiled AT cables work fine with a passive adapter. Naturally, you want to sell your USB conversions, but if you are talking to newbies then you could mention the SDL-PS/2, at least in passing.
Last, make a bigger deal of the bolt-mod and the opportunity to change layouts. That is the single most difficult thing that holds most people back from doing what you do.
You might also offer to activate "secret keys" if someone wanted to commission a special project.
