Question: is there a type 1 motor in this BUS?

When a fan belt breaks on a type 4, your battery dies, not the engine!

Given you have a type 4, w/ no compresion, cause of death unknown.

The cheap charlie rebiuld is new rings ~$40.  
   (not worth your time, unless your stranded in a desert)
The next step is new pistons, rings, and cylinders ~$300.
   (adequate for 1.7 and 1.8, but 2.0 heads drop valve seats
    so your fresh rebiuld will have a limited life span)
Next is pist,cyl kit and new heads ~$650
****(this is my recomended approach.  The lower end of a type 4 motor will 
easily outlast 2 sets of cylinders.  I have read, "to destroy the lower end 
of a type 4 motor with a stock setup, is comparable to destroying an anvil 
with a rubber mallet")
The no holes barred approach is to purchase a complete rebiuld ~$1500

Note: solutions 1 and 2 assume you have determined the compresion problem is 
not with the heads.

Another viable option is to scour junk yards and shows for a motor ~$300.
You can get one from 
  a bus from '72 through '78 ('79 if it comes w/exhaust)
  a station wagon (not sure of years)
  porsche 914 (all years 70-76)

The best motors are '78 Bus (hydros) and 914 2.0 (most power)

Your Fuel injection will work well on any of the above.

Good luck is saving Matilda

Martin