Vintage Alignment Systems
I made my own toe gauge with square tubing, brackets and 1/2" EMT with some thumbscrews.
WAY easier to use that the side of tire blocks.
Slide it until it hots the inside of the tire, or wheel, tighten the screw.
Measure the front, measure the back, subtract the difference.
If uneasy, jounce and/or roll back and forth, and do it again.
I think I got $16 bucks in it.
HF sells a magnetic digital angle finder gauge for about $35.
Getting it on the wheel is the hard part, but can be done.