Hello Shane,
Yes most of the standard gear boxes are basically the same.The first gear ratio varies a bit. First gear ratios of 1 to 4.42, 1 to 3.96 and 1 to 3.64 were used during the era. You may have to change two bolt off items, If the sedan box is a column shift, unbolt your original top cover and use it on the sedan box. Also the rear cover may have to be changed. Some sedan speedometer cables, exited the rear cover in a different spot. No big deal here. Make sure the box is off a Finback, Mercedes sedan W111 or W110, or the very eariliest W108s, after around 1968 the entire design changed and the newer version standard transmissions had three shift rods on the side of the transmissions.
Joe Alexander
Blacklick, Ohio