Fascinating subjects. I've got a bunch in my stash, but I don't ever seem to get around to building them. As kits, racing planes are pretty idiosyncratic.
Here's a Schoenfeldt Firecracker racer kit, Williams Bros. 1/32 that my good friend Dave gave me for Christmas. I have never known of this a/c, but I read the instruction blurb and then of course did some www research.
Here's a Airfix 1/72 Supermarine S.6B that Sean gave me. Still labeled $ 1.00 on the bag.
Card Model Macchi M.C.72 in 1/24. Bought that for a Swanny's Floater GB but it needs anew set of skills.
The Hawk 1/48 Curtis Racer and Travel Air Mystery Ship. I picked these up at a table at Reno in 2010 when I helped my late Father in Law go to his last Air Race.
By the way I picked this up at a show the other day, thinking about Don's Midget in the magazine
Speaking of Reno, the Galloping Ghost. Taken in 2010.
I'm game to build any/all of these. I wish i had more books too. Don, my FIL, passed on boxes and boxes of programs from Reno, hats and other swag, and thousands of photos over the last fifty years.