Thanks, Joe! Glad you like it.
Grubby, here is a beefed-up version of the bumping:
This is 37% opacity (instead of 17%), which is way too strong IMO. What I'd recommend though, is that you compare the drawing I showed previously with the one before that (which has no bumping). If you have the impression the last one looks more worn out than the previous one, then I have achieved my goal.
I like to use extremely discreet effects which do not stand out but give an overall "feel" which looks right. Especially for weathering, which is made up of different wear and tear symptoms, which don't stand out individually (paint chips, distorted metal, corrosion, paint wear and fade, dirt, scratches, exhaust staining).
Weathering is still one of my priorities as I am not very good at it.
