Repaired/puttied bumpers that would be iffy for replating can now be airbrushed with Alclad or Molotow pen refills, or sprayed with Spaz-Stix. Same goes for parts cast by beginning casters, which may have flaws as-cast until they get in more practice and get better at it. If you are really into a particular subject (early Corvairs, for example) you might cast the hard-to-find small parts yourself and sell/trade extras to recoup costs. Parts might be obtained from these folks also, though when you see them you'd better get them, because they may move on to other subject matter once they have the parts they need. Two "so-so" projects might be combined to make one really good one, with the leftovers combined and sold/traded to someone else. Unavailability of previously easy-to-get replacement parts might open up a price/demand gap between easy-to-rebuild projects and those that need more work because show goers will now be looking at potential buys with a more critical eye.