the transmission on my trusty '67 kombi/camper has developed a rather
distressing leak. I had noticed for a while that trans. oil seemed to be
leaking from around the shift linkage coupler, but it had never been
more than a drip. However, when returning home along the highway
yesterday, I stopped at a rest stop, and noticed immediately a growing
puddle of transmission oil. I am fairly certain it is leaking from the
front; Ican see more of it there, and I can see where it has splashed
back along the engine, frame, etc. Imade an emergency refill there, and
checked again this morning after letting it sit all night. The level is
again about 1.5-2 inches below the fill hole on the side.
I need to know, please, 
     Is there some seal or bushing I need to replace?
     If so, what is it,
     and, how do I replace it.
Thanks in advance.
     Richard