Not to nitpick, but the weakness of that hat stretcher is it turns a regular oval into a long oval. But, still great work!!
A great stretcher is made for each hat size, with the diameter when closed, right under the size of the hat. It slips in, and then you crank it out slightly to stretch the hat.
I have a set of vintage stretchers, each one made for a particular hat size. From 6 1/2 up to a size 8. Took me years to finally complete the set, from ebay.
Not knocking your work, just giving you some ideas on how to make a better one.
Most of the time when you re stretch a hat, you stretch it out, and then steam the ribbon area heavily. This slightly dampens the leather, and then when it dries on the stretcher, the stretch will stay. If you do it dry, my experience tells me, within a day, it shrinks back down. The dampening seems to help out in making the leather stay the right size, for longer.
