Okay, I can see how you could do all of this work without splitting the cases, but why one would I don't know.
Once the engine is out, disassembly is pretty straightforward and the head and jugs are secured with bolts on the same lengthly studs. The bolts on the studs clamp the heads on and the heads in turn clamp the jugs into the cases and all of this at very low torque values. Once they're out of the way, the cases are secured with a relative few large fasteners.
Splitting the cases makes it possible to mic the cam and crank and to replace the main bearings, which I would think you'd want to do, not to mention that you'd then reseal the case mating joint on reassembly. Some will tell you that the cases should be line bored to ensure perfect crank to case alignment.
This sounds like a half-arsed rebuild that needs to be redone, but for $2300.00, that is not unreasonable. You at least know what you'd be getting.
WRT what the engine should sound like, I honestly have no idea. Our lone VW was a Vanagon with the Type IV. In the Vanagon, you can't usually even hear the engine since it's so far back and is buried under the luggage space in the back and covered with a huge metal hatch (allowing easy engine access when removed) which is in turn covered with a thick carpet mat.
