[ltp] Thinkpad Model Numbers

[J Paul Richardson]

I have an TP A31 model 2652-XXJ.  This one was factory refurbed by IBM. 
Unlike all of the other IBMs I've seen, the model number on mine is a
little sticker that looks like it was placed over the original model
number on the standard large IBM info label.  I tried lifting it up to
see if this was in fact the case but the paper started tearing and I
figured I'd leave it be.

So my questions are: 
- does anyone know what IBM's number scheme is; ie - do the numbers
decode into anything in particular?
- does IBM renumber factory refurb units for tracking purposes, etc?

Thanks in advance,
J Paul Richardson