I have in my grubby hand a flier from All German Transmission 
(800/995-7280) that details a plethora of rebuilt transmissions for 
us van, audi, MB, BMW, and VW types from 1961 on.

for example an 83-91 vangon trans sells for $795.  $300 core
a 61-67 4 speed center section is $495 with your exchange.

the $100 offer is a coupon that expires 6/1/96 and is good on the 
purchase of any trans over $500.  i'll mail it to the first person 
that wants it but it may be available by just 'asking' for it over 
the phone.

don't know a THING about this company.  yer on yer own.
-dan