sounds like you are recreating a 50s 24h of lemans grid with the track in its original layout (would be cool).
Oh boy, I wish it was only Le Mans. What I'm doing is essentially race-by-race specs and liveries and cars for all the WSC races (including Le Mans) from 1950 to the late '80s (until Gr.C died, essentially) and then moving on from there to the '90s. That includes events with huge entry lists such as the Carrera Panamericana, the Mille Miglia, the Targa Florio, the Nurburgring and so on, from a time when there were at least a hundred cars each. Even obscure WSC rounds such as Venezuela are being done.
A lot of cars were made through the years by other people, but they always were from different events, never a complete grid. And a whole lot more don't exist (yet) to begin with. I'm rectifiying that, but 10 years and +5000 cars later, I've still got a long way to go. When you think about the 250 GTO for example, you always think about those few iconic liveries you see here and there on photos or scale models like Hill's Goodwood car or NART's Le Mans entries. But then you start doing your research and you see that the car competed, collectively, in more than a couple hundred different liveries, often from the same teams, but always with different numbers, small details that changed from one race to the next and so on. Multiply that for each car, and you see why it's a mammoth project. And then, I have a personal fetish for backmarkers and obscure entries that did one race and that was it, and I can't pass on them. I need to make them, even if nobody cares. The hardest part is to actually build cars that no other modder made before so I'm making my own from scratch aswell. White Elephant from '66, Periscopica from '67, and a whole lot more, especially for the '50s, but also the '70s and the '80s.
About tracks? Well, in that case most are placeholders. Things such as Panamericana or Mille Miglia are impossible to make for any game. No way in hell a game currently available can handle the entire countries of Mexico or Italy. But there are a few options set in those countries, smaller stages or tracks that give a period feel to it. Le Mans track set in the '50s? There is that new project in beta form available for rF2 set in 1967 with the option for 1970 aswell. A friend of mine is in talks to get permissions to convert and adapt that, eventually. But I'm not the one doing the talks, so I have no idea how things are going on that front. Regardless, the old GPL '67 is good enough, if anything it can support 60+ cars easily.
And I'm doing all of this alone.