Nice to see another scratch built RIR out there. I hope you don't mind but I thought I would point out some issues I found with the accuracy. Some of this is nit picking I know.
The main thing I found off right away is you have the incorrect post 67 T1. Yellow is yours. Your T1 is actually following the later pit exit which was old T1. This changed in 67 when the drive under tunnel was built along side the pedestrian tunnel. My point is this tighter T1 never existed with the larger T9. There were a few years when the new T1 existed with old T9 (67-69) but never the other way.
A few other things are the esses aren't quite tight enough according to the data I have and used on mine. Again yellow is yours.
Westworld and East Line are not correct.They should look something like this. Your westworld is not shown here and you are missing east line. You are also missing the wide entry to 7A shown below. Some layouts such as "spike" have you run backwards down the can am straight and enter 7A as a left turn.
Also you don't have any hills on the way to T8. You should drive through a "valley" right before you start braking for T8. Here is a cool 70s shot of them. This is before westworld and east line were created. And the fence on the left was gone in the 80s and grass had grown in there.
And the final thing is the hill on the back straight is a bit too far down the track. It's not a huge deal on the full circuit but it changes the exit of 7A on the short circuit. Here you can see the difference where the elevation changes. Yours is the one highlighted. Oh and the back straight is a tad too wide.
By no means am I saying my version is 100% accurate but it lines up to the data I used which I stand by 100%. I don't expect you to make these changes but I figured I would point some issues out in case you cared to know. You are more then welcome to use my model as a reference.
Shot of them side by side.
Final comparison of my esses and a real photo from 79.
