You could have exact remakes of those forks made for pretty cheap, I can waterjet the two plates for around $10 each, you could go to any iron shop and have them bend you two peices of 7/8" mild steel tubing and weld them together in about 10 minutes.
Torch straightening is the other option, just be careful not to collapse the tubing when you go to bend it. Don't bother trying to temper them after heating, they weren't tempered when they were original, and heating them with a torch does nothing different than what the welds did to the steel when they were made in the first place. Quenching them with a hose will not temper them anyway. To temper mild steel it needs to be completely and evenly heated to deep cherry red (around 1100F), then oil quenched, then placed in an oven at a lower temperature around 500f to allow hardening to occur. Tempering/Hardening increases tensile strength (stretch), but reduces impact strength (Snap). There is no way to evenly heat a part that size with a torch, don't bother it won't gain you anything anyway.