I still have the 550 apart and the original rearend. I haven't swapped everything over yet. I still need to get the rims/tires and a few other items off the original rearend.

I bought all the parts (seals, gaskets etc) to get mine back together but haven't had the time. My shop isn't heated so the project has taken a back seat to others. 

I'm guessing you saw the photos and read the story then. Somebodies great idea for a shade tree mechanic fix could've worked, they just forgot to tighten up the nut on the countershaft (or stake it from spinning). No second gear in that fix. I could've tightend that nut and resealed everything and it would work, but I want second gear. 

Both rearends are opened up, no top covers. You can see the gears for everything. I'm not sure what your looking for but I can take pictures. 

I'm learning transmissions as I go, I've already had a self taught lesson in 1800 series B hydraulics. 

I'm an aircraft mechanic/technician by trade. Grew up farming (just outside of Moorseville, our farm was at the corner of 975E and 800S, airport ground now)  I belong to the Hendricks County tractor club. I own 3 olivers (1800, 1650, and the 550) two oliver implements (520 baler and a disc). I have a fourth oliver tractor 88, that I sold but its still here. I may still own it. I also have a Ford 801 diesel tractor. 

Niether rearend pops like yours. I saw your videos.

Jeff