For sure, someone in the Ford old car world has one of those bearings sitting on a shelf.
Yes, they are hard to find and very pricey if you do find one for sale. I am convinced that a modern day
encased in rubber bearing could be adapted to fit inside the 41 torque tube. The idea would be to drill and tap the torque tube for several 3/8 x 24 set screws which would hold the bearing in place. A second retainer could also be made and fitted inside the torque tube so that it pressed up against the center bearing. That retainer would also be held in place with set screws. It would be worthwhile to experiment on an old torque tube.The OEM center bearing uses roller bearings thru which the driveshaft slides. It's not a tight fit.
https://www.fordbarn.com/forum/showthread.php?t=186780
and peruse this:
https://www.google.com/search?q=rubb...hrome&ie=UTF-8 and something like this that could be adapted if the ID was correct.
My experience has been that the OEM center bearing itself doesn't fall apart or wear out. Instead,the outer rubber case deteriorates rendering the bearing useless and it literally falls out of place. In the photos below,the big black blob is the dissolved rubber.The metal bearing buried in the blob was still good. I am thinking that there must be a way of making a new rubber casing of the required OD so that the old bearing could be reused. With today's polymer technology perhaps a rubber compound could be poured around the OEM metal bearing ,making it reusable. For instance, the polymer used for making skateboard wheels. It would be fun to try. Last photo is of the tool I made to install the new OEM bearing. Without the center bearing,I think the whipping action of the drive shaft would put extra wear on the needle bearing at the front of the torque tube. Not good.