I happen to have exactly what you need and since I don't have a M36...... Only problem is distance.
Still, this shouldn't be too difficult to solve there, with a bit of luck and patience.
Here are a few facts:
1) The M36's wheelbase is exactly 36" longer than the M35's (190"vs. 154")
2) The M36's (TC-to-FWD-rear-axle) -driveshaft is a two-section driveshaft, supported via a center bearing asembly, aka pillow block.
3) The
rear-section-DS is exactly the same as on every M35 in this world.
4) The
front side of the
front-section DS is identical to the
rear end of the M35 DS. The rear side has no slip-joint but takes that pillow block and a companion flange (#13) which is the same part number as the ones on every Deuce differential (#7521276).
5) The distance between that companion flange(face) and the (#19) front yoke's face is... you guessed it: exactly 3 feet - which is no surprise, of course.
If I had to build me one such "intermediate" driveshaft I would cut a stock M35 DS to correct length and weld it to a splined shaft, possibly a rear output shaft out of a scrapped Rockwell T-case, modded. The companion flange & nut would be there, also. The rest of parts like bearing/bearing support, etc. should be easy to find in most every truck junkyard, and eventually adapt a bit (I think...)
Attached some pics...