If you were prepared to scavenge for objects and scenery that needn't be an obstacle? You'd have to credit the original authors, but with two sets of extra graphics for sixties Imola itself, as well as all the other stuff, you could make it fairly decent? Nineties Imola might be more of a problem though.. There's a project I've been tempted by despite having zero knowledge, since it seems fairly limited, the reworking of Suzuka to the sixties layout with sixties scenery- but there might be a lack of Japanese scenery. There should be enough European scenery though!
Yeah, modern tracks are more tricky because it's hard to make them look modern if you use the majority of GPL tracks to get objects from and doing 3D and texturing myself I'm just not willing to bother I guess. Besides, with 4 chicanes in it Imola 94 wouldn't be very favorable for 60s cars, except 69 mod perhaps. Not to say it's not interesting to drive at though. If I find motivation I might try to make a more finished version eventually.
I didn't know Suzuka existed in the 60s, what was its layout? From what I know it was built by the same designer that made Zandvoort, wish he was alive and working on modern tracks instead of that Tilke guy...