Thanks for releasing this. Its great to see some older car mods.
To add to some of the feedback, I don't think the tyres need more grip. See what Oskari manages to do with the Auto Union.
If you are looking for feedback I've added some below but please feel fee to ignore. None of it is very important, I'm just glad you released the mod. So please feel free to Ignore this below.
Based on my very brief testing I did notice a few small things, at 30s Spa on default set up.
The Mercedes is much more prone to snap right oversteer than the other two.
All cars, even cruising on straights, have higher temps on the left rear versus right rear but then opposite on the fronts. E.g higher temps on the front right versus front left.
These last 2 might be VR only but the default driving position of the Mercedes is very far forward whereas the Alfa is quite far back. The side mirrors are very distorted.