My nephew took a job repairing some old wooden wagon wheels for his neighbor. Overall the wheels were in good shape, but had 3 broken spokes and part of one wheel that needed replacing that was dry-rotted.
For the wheel replacement, I had him save the outer cut-off to use as a support on the drill press when he got ready to re-drill the holes for the spokes.
I saw in one of the wood magazines a while back how to do the round tenons on squared/rectangular wood using a jig on the router. The spokes on the small end were 1" across the diagonal, so we drilled a 1" hole to spin them in. Drilled a 5/8" hole on the bottom side where the router bit would be raised into the jig.
Basically he just had to spin the spoke around and around until it bottomed out against the fence, worked like a charm.