Shifting tower/arm on my '42 PU-New info

[rotorwrench]

They should be rounded at front and rear so they can apply even shifting motion through the whole range of fore & aft motion for the low reverse on the 3-speeds. They must be able to fit into the slot on the fork too. They can be somewhat flat on the sides since that only locates how far they seat into the slot on the fork. The High & 2nd gear nub is cylinder shaped like a horse pill so it can also exert the same smooth motion in fore & aft movement inside the slot of the big fork that fits into the synchro ring.

I've built them up with brazing rod and smoothed them back out when they start to get notchy and flattened out too much. They have to be able to push the fork rods into the detents for sure plus you don't want them to be too sloppy.