Welcome!
I don’t know if the place is still in existence but I remember this much. When you take the Bloor subway line (Green Line) to the Kennedy Subway station there is a stop called Greenwood. Nearby there, there should be a do it yourself shop. I’ve never seen it, but honestly, judging by the quality of shops in the surrounding area I wouldn’t think it’s anything better than the one you went to in Brampton. I found it in 2002 when I was looking to find a place that would allow me to replace the Floorboards on my Datsun. I will try to find out the name again.
Other than that, what is the name of the place that you found in Brampton? Do they have hoists and large tool rentals? Is it heated?