The shafts of the 70's era MB trucks were metric. I changed the wheelbase on a lot of them to better accomodate van bodies and had to cut the drivelines. The u joint parts were a european product and we came up with a Spicer driveshaft that worked.
Incidently on Jerry's comment about runout we held ours to .005 at the weld yokes nad midship stubs and never had a driveshaft come back for any reason. I did not have a balancing machine and know for a fact that it is a production shortcut as getting them to a very close tolerance we held is time consuming but it works.
I too have never heard of anyone successfully straightening a driveshaft. They must be retubed or replaced. A tube & yoke [censored]'y will save you money over just replacing the tube.
