Mine is an ali casting thats been split into 3 bits & mounted on two hinges. The central bit is fixed mounted, you start the scroll & lift up the other two sections after you have scrolled past the first bit. Using a split scroller keeps the scroll you make flat.
I looked at buying the jigs in the past but as stated above they seem a bit thin for the price.
Anyhow, we're in the fabrication hobby/business so I'd rather make my own as 'time' isn't a 'cost' for me, as I suspect it isn't for most of us at the hobby end of metalwork.
I met a guy on the local car boot/market a couple of years ago and he was making hanging baskets, etc. In between serving customers he had a rig attached to the back of his car and he formed a few scrolls. It got people interested and talking to him and helped the sales as people could then see that everything was home made.
His scroll jig was half a dozen old sockets bought from the same car boot at 50p each then screwed onto a piece of wood.
Thanks for all the links above, there's plenty there to think about!
If you only want to bend 3mm flat a lightweight former like this will be ok,
Ive made hundreds of scrolls with it, its mounted on a square box section so if you're tight for room you can turn the former in the vice.