Gee, I'm interested in everything I see in that picture.
Very cool looking mini bike. First I've seen like that.
I can't make out what the blue curved shaped pieces of steel go to, but since I've been thinking lately about making a side car, I immediately started thinking in that direction. I see some sort of motor with a kick start there and wonder if it's attached somehow to the blue curved steel ?
Anyway, if he's willing to sell that hound dog roller, and you are able, you should jump on it. Good find !