go find an np208 with the flange and cardan joint front shaft. you'll have to source the flange seal but that's only 6-9$. find a long piece of tube with the same ID, remake shaft, done.
add some trans fluid to the shaft, keep the slip at about 1-1.5" each way. weld one end at a time providing time for it to cool so you don't create a pressure vessel with the oil.
tuh dah, a 40-80$ driveshaft that solves all your problems.