Hi George, give me a bell sometime as I have a fair bit of info on most of the cars you are looking for, especially old OSCA cars.
Good luck with the class I know it will take up plenty of hours. It has been mentioned by others and some are against but what we found worked for our 40th anniversary meeting was to simply let any car that had ever raced at least one OSCA event in but with a committee of 3 to decide on eligibilty. The only thin we were looking for was an obvious performance upgrade that didnt exost back in its day such as putting a 750hp 14 degree crate engine in when said car only ran approx 500hp 23degree head engine.
As long as it looks like the car from a certain period let it in or as you are rightly doing give them a chance then see where things need to be tidied up.
Handicap racing will be advantageous as at the end of the day you are putting on a show for the spectators and its those spectators who will keep the class wanted by car clubs by coming to the tracks...just like all sport sedan classes over the years (possibly not OSCA) the guy that brings the fastest car wins and the rest soon leave the car in the shed...or start another class. Puke's straight aint as quick anymore.

Was probably harder for us down here but after nearly 2 years of planning we only ended up with 7 cars I think from a supposedly 17 confirmed or at least thought they would make it. Keep on them and keep them keen!!!

Cheers Munty