You certainly came across an strange drivetrain set up ,I can only imagine the hours of work it would have taken to transplant that drive line

heres a couple of links to some busnut sites

http://www.busconversions.com/bbs/index.php

http://www.busnut.com/home.html

lots of knowledgeable fellas - some one will be able to answer your questions

That drive line if in nice shape/documented history could bring some $$