Man, does that ever bring back some memories? I saw a shop in Spokane once that had a truck frame hung from a chain hoist hooked to a big tree branch. It's wild what people can make work when they have to, but it also makes you wonder about the quality. I'd be nervous getting a car back from a place like that, you know?
You know coracarter, I get where you're coming from but I've seen some real talent come out of those backyard setups. My uncle used a similar rig with an oak tree to straighten his old farm truck's frame after a wreck. That truck ran for another ten years with no issues. Sometimes it's more about the skill of the person than the fancy tools they have.
Seriously though, that's playing with fire. A tree branch isn't a calibrated shop press. Just because it worked once doesn't mean it's safe or right. You can be the most skilled person alive, but using the wrong tool for a job that critical is a huge risk. I'd never trust my vehicle to something that could snap and cause way more damage.