Making vintage tire sizes from modern tires.
 

I needed runner tires for my old Optima mid Ferrari F40, 1.9" touring car tires are way too narrow and small, but 2" tires are extremely rare so I tried making my own from some modern WR8 57x80 tires: https://www.aliexpress.com/item/32980234411.html

I cut away three sections of thread and glued them back together with thick CA. I worked great. They were tight on the rim after that but didn't break as I stretched them on. They fit perfectly though. I drove around with them without issue.
Video of the car runing with the tires:
https://youtu.be/jDE3xh8-G9s


Now I needed front tires for my Playtron Lynx and used some Kyosho Scorpion tires. I cut away the center thread and glued back together, one knob at a time.

I'm pretty sure people used to do this back in the day to create custom threads. It's not hard. It doesn't have to be absolutely perfect.

Skip to 0:45 for some tire modding: https://youtu.be/qG7hVqmnMP4