1940 trans shift levers swapped

My transmission was rebuilt recently. It seems fine while driving, no grinding or crunching noises or jumping out of gear or anything, even going up and down a couple of mountains. The only things I noticed were the shifting felt a bit different, hard to quantify, and there was an annoying clack when going into 1st gear. This turned out to be the shift linkage striking the body floor bottom.

I opened up the hump cover and trans and saw that the shift lever (teardrop shaped thing on the selector shat) was swinging almost all the way horizontal in first and allowing the linkage to rotate far enough upwards to hit the floor. I temporarily glued a rubber pad to the floor to quiet it down. Further research revealed that the shift levers are swapped left to right, i.e. the short 2-3 lever is on the 1-R (left) side and the long 1-R lever is on the 2-3 (right) side.

So I contacted my mechanic and he will fix it. We are thinking the selector lever can be R-R'd with the trans still in the car. Unfortunately he is 70 miles away so I probably will not be able to get the car back over there until next Spring. From watching it function as I go thru the gears I think 2-3 shifting is OK but I may have be careful of 1-R shifting possibly not fully meshing, although looking at it from above it seems to be meshing properly.

So a few questions for those who have had their hands inside these things.

1. Can the selector shaft be removed and replaced with the trans installed? This is the one that goes across the trans. It is suppose to be driven out to the right and installed from the left because of the oil seal.

2. Am I OK driving it until next year? I doubt I will put more than 100 miles on this winter.

3. If anyone has one of these 5 bolts jobs on their bench right now, if you could measure the amount of 1st-rev gear movement from neutral into 1st and neutral into reverse that would tell me if my gear is being thrown enough.

Cheers, Dave