Our PC is a 2007 model year 2350 with the ever common 4000 Onan. Just as described, access is limited, but it works.
A few years ago, I had to replace the generator fuel pump due to it consistently overheating and shutting down after roughly 20 minutes of operation. Being that the fuel filter is attached to the fuel pump, it was the right time to replace that too.
I consider myself mechanically talented, yet I found the project challenging. The challenge is within the generator itself, not from the reduced opening of the access panel.
"A WARNING TO EVERY PC OWNER"
Because we have an obstructed view of the generator, a few PC owners have mistakenly installed the generator cover incorrectly and lost it on the road. The generator needs the cover mounted properly to cool properly, so if you lose it, you'll need to buy a new one. A new cover is not readily available and is expensive.
When reattaching the cover, make sure to first set the bottom of the cover in the grove on the generator (not the mounting frame as is easily mistaken) and then latch properly. The two red latches twist 90 degrees in opposing directions to latch and unlatch.