UPDATE
For anyone looking to see what is different in a grey market B6000 transmission, i've discovered the following differences so far.
012 - 66611-14252 - GEAR 15T is a GEAR 18T
013 - 66611-14260 - GEAR 19T is a GEAR 23T
015 - 66611-14280 - GEAR 13T is a GEAR 14T
026 - 66611-14350 - GEAR 17-21T is a GEAR 20-25T
035 - 66611-14442 - GEAR 17-21T is a GEAR 20-25T
058 - 66611-14853 - SPUR GEAR 18-22T is a SPUR GEAR 22T
I have a broken 015, damaged 058, broken 037(GEAR 29T), damaged 029 (4TH SHAFT - HI/LO gear won't move all the way to LO) and bent 045 (REVERSE SHAFT) .
As far as I can tell, 037 is the R/1 selector gear, 015 is 1st gear, 058 is the reversing gear which drives 012 second gear backwards.
035 is 2/3 selector gear, 012 is second gear, 013 is third gear.
028 and 026 are the PTO gears which are driven by 015 (1st gear), 012 (2nd gear), and 013 (3rd gear) respectively.
I have a feeling that I cannot just change the broken gears since they are different tooth counts. Please correct me if I'm wrong on this. I'm hoping that if I change all of the gears that are different then it will work. I have found all of these parts used and am looking at $1200USD. I've also found a donor B6000E transmission which has all of the parts I need minus 1 shaft for $500USD + 150USD for the shaft, but I can't know if the transmission is any good (he thinks it's OK).
This is getting pricey since I still need gaskets, seals, and possibly bearings.