I race Club Ford vintage races... (check out Royale Formula Ford Challenge Series in the race org category) no interest in the costs associated with SCCA (and there is maybe more wear & tear in SCCA)
I copied your first post and my comments are all in parentheses.
Class name: CFF
Engine make: Ford
Engine model: Kent
Displacement: 1600
Power at crank, HP: 115 (if you're lucky and you've bought a $10K engine. 105-110 is more accurate for mid-pack)
Torque at crank, ft-lbs: 110 (see above - more like 100-105)
Weight with driver, lbs: 1,110
Purchase new, $: 6,000 in 1974 = $30,000 today (you can buy a vintage CF for $12K-$16K easy)
Tires set, $: 490 (American Racer) (Hoosier treaded - about $600 a set, but usable for 5 or 6 race weekends of 6 sessions/race weekend)
Tire competitive heat cycles: 13 (see above)
Engine rebuild, $: 5,000 (yes, as noted above, more like $7500 if you include the head and carb)
Engine competitive hours: 53
Fuel $/gallon: 4.50 (I buy non-ethanol 93 for about $3.50-$4/gal, add one gallon 110 leaded at about $7/gallon)
Fuel gallons/hour: 6
Brake pads set, $: 188
Brake pads hours: 13
Other operational costs $: (chassis setup $600-$1400 every two or three years or if you have an incident; $300-$800/yr - normal R&R, such as rod ends, spherical bearings, wheel bearings, spark plugs, oil & filter, hoses, lines, fittings, etc., and stuff you want to improve because you saw another guy had one/them - those fancy shift linkage joints are $100 a pop, for instance)
I note you have not included the trailer ... anywhere from a used $2500 trailer you then put another $500-$1000 into to get it like you want it, or multi-thousands $$$$ if you indulge yourself.
I can't afford it, but I do it anyway because, at 60 (2 years ago) I saw many friends who could no longer even attempt to do the things they kept putting off until "...some day." So, what Sean said above, for sure.