I was about to re-iterate the rear toe issue, but it seems you are on the way to a proper fix
Rear wheels toe'd the wrong way do indeed cause the car to crab.
It must have been a fair way out though.
My guess is someone has 'drifted' it into a kerb at some point bending the toe arm.
No doubt they tried to bend it back with heat.
Oh well, it'll be like a new car to you afterwards