I made the checklists. (This is the only website on the net with an accurate listing, or at least the most accurate) I worked very hard to make sure they were accurate. There are not missing cards. Keep in mind that the checklists only have the CARDS, not a listing of every car made. Not every car got a card.
Please give an example of the random scans you mention. Racing Champions used the same two designs interchangably from 1990-1995. The only way to tell which one goes to which year is to see them still in the original packaging. It's possible someone has entered scans incorrectly- they are incredibly hard to get straight if you don't research them. Even though they are my specialty I still did make a few mistakes in the listings and scan posting, which has since been corrected.
The only "cleaning up" they need is adding teams and possibly a few PIDs for the non-NASCAR drivers.
Edit to add: There are still promos that are indeed missing. Every so often I look through ebay and find another one that has gone unnoticed for the past 25 years or more, and they are not yet listed...but I have added them in when I find them. Every standard release (base set on here) is 100% accurate.
VERY slow trading due to health problems. Not transferrable so safe to trade with, just moving is painful and can't always access the cards.
Cardboard History My COMC
New Collection Website: Cardboard History Gallery (Still under construction)
Tips on how to make your scans look like the card does in hand (No more washed out, fuzzy scans!):