Here's an update on how the 1872 is doing.
Picked up a new reproduction seat off ebay; great quality and price.
Old:
New:
I redid the drive shaft. I initially bought a drive shaft off ebay; turns out it had a slight bend in it which created a little vibration. To make it worse, when I made my hydro coupler it ended up being slightly off center...which created even more vibration. It was ok for a time but need to be redone.
A shout out and thanks to Sam Mac for hooking me up with a factory hydro coupler!
Old drive shaft top, new shaft bottom. Cut off the end spokes and rewelded them to the new shaft.
Hydro shaft tapped and coupler installed. New drive shaft painted and installed. This thing is straight as an arrow now.