on brittle nature of PVC - i dont think it would be a big issue - i ran
a 2" PVC under my 71 loaf for about 5 years without a problem and it got
hit by lots of junk.

Its a close call - if i were looking at this job and the VW parts were
$260 i think i would go with the OEM parts. There are bound to be surprises
when you fabricate something new in my exp. On the other hand i dont
know how many more years i can expect from my 83 until the cancer
catches it - still nice now but once it starts its exponential ......