There's no way they should need 5 weeks to do that job.
When I needed my driveshaft done (to mate to the Ford T5 for my 5.0V8), the local driveshaft shop had it done by the next day, and they redid the entire front half of the 2-piece shaft. They chopped off the mazda shaft where it mated by the center bearing, and welded on a new front shaft, and then welded a new yoke to the end of the shaft. Pretty straight forward. It was about $300 because the yoke I had wasn't in great shape, so they had to put a new yoke on. I originally mated the mazda driveshaft with the front 18" of a Mustang driveshaft myself with my crappy little welder, but didn't get the balance right because I had a vibration at 60MPH, so I eventually had it done right.
^^^ I did the same thing, MY local place had mine for about a week, took 3-4 days of research to make sure everything would work and BOOM the next day it was ready, was almost $300 but I was ready to pay for it. Last thing I wanted to play around with is something under my truck spinning at 60+ MPH.