Old Toy

[anaxcrosswords]

When my brother and I were kids we were bought something which I thought was called Multi Rig, but I can’t find anything on the web by that name. We’re talking about maybe late 1960s/early 1970s.
The toy came in packs of few dozen sheets of thick cardboard which – to us at least – were quite big, possibly A2 size? On one side they were either red, yellow or blue. The reverse was white but with, in black, simple illustrations to represent things like wheels, doors etc. Using an assortment of white plastic clips these boards could be constructed as pretty much anything you liked, but typically a car or den.
We had a basic version – there was a more expensive one in which some boards were triangular.
Anyone remember it?