We used to own a full size Aveling DX8 roller, it was a lovely machine to drive.
I too came to the conclusion that a 1½" model would not be capable of doing much work, and so decided to make a 3" scale version back in the 1980's, I got as far as finding the thick walled tube to make the rolls from. However because of other commitments it never came to anything and those embryo rolls ended up as planters in a friends garden many years ago.
I still have an original Aveling General Arrangement drawing for the roller somewhere in the loft.
Phil