>Hello all.  Any ideas on how hard it would be to convert a regular bus to a 
>camper bus.

Go for it, just forget the pop-top, it's too much work/risk.

like a previous post, you need to drill some holes, large holes, 1 1/2 inch 
through floor(s) depending on location. Maybe cut a square hole with jigsaw, 
then get a piece of sheet metal + inner tube gasket made up to fit pipe to 
floor. Or fit an adapter to the plastic pipe and add a more manageable size 
3/4" flexible tube. Don't drill a roof vent, that is only if you use the 
drain pipe that runs under the van for a holding tank, I just dump to a 
bucket/gutter depending on circumstances. Don't bother with the electrical 
hookup, not worth it. Just get a good extension cord and bring it in via the 
front door sill.
        If the interior you saw is like a '71, maybe swap the position of 
the rear facing seat and the sink/cooler cabinet. Turn the cabinet to open 
into the aisle. Your passenger can then reach the fridge when seated. This 
also allows you to easily remove the rear facing seat when you want to lug 
large objects/ need floor space for entertaining.
         Take the louvered windows and surrounding seal, they are a real 
easy swap over and make a huge difference in flow-through venting when 
camped. The screens are useful and damaged ones easily rescreened with 
better finer mesh.  One word of caution, if you are drilling into the rear 
area to mount the bed hinges/brackets DON'T drill into the gas tank!
         Take >> everything << from the old Westy, including the wood 
panelling AND the galavanised rails that hold it in place. Roof is optional. 
Get all the screws etc. If the panelling is scruffy, sand off the vinyl 
laminate, and you get real plywood underneath, which you can refinish in 
some suitable stain, lighter colour the better. Try to snag the gas heater 
from the engine compartment, including ducts and dash switch+relays, it IS 
camping equipment after all.

        This adds greatly to the value of an old bus, provided authenticity 
isn't of more value, and it still seats 5 adults in comfort.    tim s.