I have seen something similar used as a starter for racing cars that would otherwise be push-started....
Good show, Roger....correct!
I saw this one used to start a Bugatti Type 35B, which must otherwise be started by a handcrank (no self-starter). The Bug has a high-compression straight-eight that is probably much more of a chore to crank than an Austin 7!
In the picture, the welded re-bar pieces are part of a "ramp" that is folded out, allowing the car to be pushed up onto the rollers.....it works quite well!