To answer the question I am most frequently asked: Sorry, no, I don't know where you can get your own copy. It's long out of print; and as I say on the front page, until I bought my copy at a local rummage sale, I'd never even heard of the game.
However, that said, here are a copy pieces of advice:
Needless to say, a little hit and miss, but copies of the Rubik's Race show up there occassionally.
(But, given that you found this page, you're probably already doing web-searches...)
Especially if you (or a friend) were skilled at, say, woodworking or some related craft. Even cardboard or some such --although unless it were really good carboard, it likely wouldn't stand up to the punishment for very long.
Again, sorry that there are no real answers here. But I hope this has been of some help.