Model cars and rec-room floors

I tried a lot of things to improve the scans of those Marmora station negatives, but nothing seemed to work. I put them aside and tried scanning the negatives of some old model car shots I found in the same box with the station photos. These ones were shot with an old bellows camera - probably of a late '30s or early '40s vintage - that used 120 roll film. I recall setting things up on the rec-room floor in my parents house and spending lots of time fiddling with a light meter and floor lamps. I processed the negatives, but never made prints - well, I can't find any prints. These digital 'contact prints' are the first I've seen of the shots in a long time. Over on the right is a Tommy Ivo rear-engine dragster kit I was especially proud of because I think I tried to wire the engine. In the middle is a Revell Porsche kit that I still have, and over on the right is some sort of long gone hot rod that I can't recall building. The station negatives don't look too bad to my eye, but the scans are overly grainy. I need to spend some more internet time figuring how to improve them.