My post from 9/16/2013:
It's according to this site that I conclude that the 12456 seal is correct for the 1 1/4" shaft, 2" OD and 1/4" width.
As I recall, 11800's are for 1 1/8" shaft. My 1 1/4" axles tore up the 11800's before I figured that out. I suspect some sealant on the threads of those 4 axle mounting studs would be good too. I didn't seal round the shims and it looks like I may get to take it apart again! Oh well, I should have put in new brake shoes or linings anyway. Where's a good source for new or refurbished shoes?