As Larry said, you can repair the locks rather easily.  I'll add some to
this, though.  The door handles remove *very* easily.  The front doors
have a single phillips-head screw holding them on.  Open the door, and
look at the rear edge near the door lock.  There is a little part-circle
cut out of the metal lip of the door.  This is to make access to the single
screw easy.  Gently pull the rubber away from the door in this immediate
area, and you will see the screw exposed.  Unscrew it, move the handle 
forward, and out at the rear.

The sliding door is a bit harder, as you have to remove the interior panel
to get at the single screw holding it on.  

While these are out, clean them up and find the four-digit number on the lock.
They vary as to their location, and some might not be well readable.  Take
the number, and one of your cleaned lock/handle pairs to a VW dealer and pay
him to cut a key to the code.  This key may well help you enjoy the bus
again, as your old key is probably worn to the point of being the wrong key.
Generally, there is a charge for cutting keys to code, but the charge is for
setting up the machine -- multiple keys should cost about the same as one
made by duplicating, so get a few of these proper keys made.

They may, on their own, fix your problem with the ignition lock, which is 
*not* easy to get out.

malcolm