Never one to rush, I've been modifying my M715 for the past 10 plus years. Wanting to switch to 24V wipers I happened onto the Gamma Goat wiper way back when as a good military alternative.
It's an American Bosch piece but has the problem of a 2" threaded shaft that required devising a way to mount the unit well away from the backside of the windshield frame. This idea went dead for about 10 years until I recently went searching for a second Goat wiper and happened onto a marine version of the motor that's almost an exact copy except it's marketed under a Dutch company name 'Vetus' and available with 2" or 1" shaft and is a two speed unit.
They are not cheap but mount up nicely with a 5/8" length, 5/8" ID nylon bushing from McMaster-Carr. The wiring was routed with flex tubing down the same path as the vacuum line to the dash-mounted switch. The stock wiper arm fits the motor spline and is self parking as shown. Plans are to paint to match the truck and probably acquire a second motor for the passenger side.