As far as Kevin's original question, "how many letterers are direct descendents of racers", I was not one...
My Dad was just a fan, and we rarely missed a week. I spent any spare time I had as a kid drawing race cars and as a Junior in high school was asked by Dan Smith (#73) if I'd letter his late model for the 1983 season. I was lucky enough to get to talk to Bill Nemec and Dennis Smith on where to get supplies/helpful hints. The following year I lettered the cars of Mike Temples (#38 Sportsman) and Armin Hess (#15A Rookie). By 1985 I was up to 6-7 cars and it continued to grow from there. I'd estimate I've done 500-600 racers since.
What is interesting is that I graduated Hunterdon Central High School with Kevin Inglin (Kevvan), who lettered his fair share of cars and another fellow graduate, Tom Birkner dabbled in race car lettering for awhile too (he did the Kuhl midget, cars for Rick Wean, Lou Cozze, Tony Seseley). Additionally, Dave Garboski of the the famed Renegade Design lettered many cars through the 80's and graduated a year ahead of us.
Which means in one two period Commercial Art class back in 1983, four of us were all headed in the same direction and competitive enough with each other to drive ourselves to be better and learn from each other about this wonderful trade.
As for racing myself, I was fortunate enough that my brother Lester put together a car for me to drive in the 2004 NES Rookie season. we finished second in points by one position to Jason Hamilton and called it a career.