My first large scale commercial track car was a 1/24 scale K&B Ferrari 250 GTO/64, so I've always had a soft spot for those type of kits. They do make a unique sound when running on the track, as opposed to the usual Mabuchi can motor powered cars of the same era. Over the years I've managed to accumulate enough parts and pieces to build at least one example for myself to have some fun with, and I've still got some original unbuilt K&B kits in my collection.
As for your project, no need to source an expensive vintage K&B body for that chassis (unless of course that's your plan). Consider converting a 1/24-25 scale model kit body for use. You can mount it a few different ways, making your own mounts from brass rod or tubing and sheet stock using any combination of screws, clips, pins or velcro to attach the body. Fortunately, the chassis has an adjustable wheelbase to help you size things up to most of the common body styles available. Building up screw posts as the originals used can be frustrating and tedious, especially if you've never tried it before, but it can be done. Also, the original K&B body screw posts had metal (brass) inserts with machine screw threads in them to attach the body.
Hope this gives you some alternative ideas. Have fun! -- Ernie :>)