I ended up having a sizable gap around the piston, which resulted in a fair amount of blow-by. I started by gluing a short dowel alongside the main dowel for the shaft, along with the blocks.

I then cut away most of the shaft itself with a band saw, and whittled what was left round. For the bearings, I just ran hardwood on hardwood, with a little bit of axle grease and oil on it.

Small wooden fishing boat plans 16
Pontoon boat seats in florida