" .... cutting them so they tend to curl.... scribing the metal and flexing it ...... "
depending on the shape, maybe you could try (shears or scissor) cutting away the waste in bit size pieces rather than cutting out the shape with a continuous cut?
a diamond pointed scribe can cut pretty much through a sheet of brass much as the back of a hobby blade does in styrene.
no end to the "ghetto - brakes" you could put together with either metal or tropical hardwoods. thinking about the rack at the big box store, there's angles, rods, and keystock. add some C clamps. i know jig & fixture making takes away from building time, especially for a one-off part. i have a box of things in the wood shop ready for the "next" time!