You can easily buy sheetmetal curlers/rollers from real hardware stores (not bunnings hehehee).
In most cases you can use the supporting groove and/or nails to hold the metal in curved forms.

Are the pics on here (when clickked-on) the full size ones? are do you have bigger ones?
Probably too big to email, but if u can upload to a host-site somewhere, i'd certainly love some bigger pics.

I've wanted to build some of these ever since having the 'bug' to build an old golf game (2c) i'd talked about in another thread here somewhere....

MM.