illinois strop numbers

[grahamule]

Hello all,
I am a newb who has been shaving with a shavette (going on the cheap) for a few months now, and am slowly making the transition to the more traditional straights. I have a wapi from thewellhonedrazor, and am in the process of getting a strop so that I might actually shave with it (the wapi, not the strop ).

My question is this: when looking around at websites, I see "Illinois #827, #127, #206, #835" etc. I have not been able to find yet what these number refer to, or what the difference in the strops are. I am guessing that they describe some kind of difference in the leather used (and therefore affect the razor slightly differently?). Any help would be appreciated.

More generally (and I have not searched as much on this question), have the members here had good experience with the Illinois strops, or better with the Dovo, or others? I know Tony Miller has a great reputation as well, but I was wondering about others in addition.