Dino, Here is a pic of my form. I was getting ready to post it on PA and saw others had helped you there.
This form is a 2x4 cut to the profile I wanted and attached to a straight 2x6. I use this one for adding backset, removing twists and straightening side to side and up and down bends.
A simple 2x4 can be used. You will have to cut it to the shape you want if you want it for reflexing.