Peugeot UO8 re-bending spread rear dropout
I bought my U08 brand new in 1973. The guys that I rode with told me that the Delrin plastic derailleurs were junk and would break. The guys were right. The rear derailleur broke - in 2018! The derailleur failed during a ride, locking the rear wheel. The rear axle broke into two pieces. The dropout on the derailleur side spread into a 'V" shape.
My question is about bending the dropout back into the original shape to form the axle slot. Should I heat the dropout to soften the steel before bending or bend it cold and possibly risk hardening or embrittling the steel dropout? If I heat the dropout with a propane torch, do I need to be concerned with affecting the brazed joints at the tube frames?
Also, I'm considering a used Suntour V-GT rear derailleur to replace the broken Simplex. It's not OEM but it is the roughly the correct vintage, has a good reputation from what I've read, and affordable. Any thoughts about a replacement rear derailleur?
Thanks