You are right, I missed that in the post, guess I didn't read it fully.
On the '39 the shaft and worm are one piece, no wear there except on the ends of the worm were the bearings ride.
The sector most likely has the most wear in the teeth since its stationary, the worm is always rotating which spreads the wear out among the teeth.
The 1 1/8" bushing on the sector is probably worn also. You can add a second bushing out at the end of the housing in place of the spacer for more support of the sector.
A good cleaning and adjustment does wonders for the old boxes. Even if its worn, the most you will have is a little extra play in the wheel at the straight ahead position.
Joe
