In the meantime while your waiting on your new hand you might want to try a little gunsmithing of your own if you would like to shoot it today.
Take a "Bobbie Pin" and make you a replacement hand spring. use a knife blade and a hammer to knock the old broken piece out that is holding the old spring in and fashion your temporary one to fit in the notch. I had to do this many times back in the 70's and 80's whent the hand springs were terrible....................Bob