The Chevy P30 chassis was used on a lot of stuff, and shares a number of parts with other Chevy trucks of the same vintage. The P30 chassis was produced in one form or another from 1969-2006 with some revisions along the way so there are parts out there, you just need to look in the right places. Locally I would suggest NAPA truck parts dealers not big box stores. Online check out companies like Mill Supply, or Precision Sales and Service in Birmingham, AL Also be aware P30 is sort of slang, and you may find parts listed as P-30, P-32, P-series, etc. Also be aware that some parts interchange between the P30 step van chassis and the P30 motorhome chassis, and some don't. Also if you need them used P30 service manuals show up on ebay from time to time, though not for all model years.
2002 Safari Trek 2830 on P32 Chassis with 8.1L w/ 400 watts solar
2017 Jeep Cherokee Overland TOAD with Even Brake,
Demco Commander tow bar and Blue Ox base plate