smokejumper,
Welcome to the Stovebolt. There is no reason you can't just replace the damaged ones, but keep an eye peeled for any obvious reason those bent ones failed. Valves that get gunked up and stick in the guide are the usual cause of this, and it might be especially true of a rig that sat for a long time.
If you spend some time fiddling around, it's possible to get a bent one straight enough that it won't turn into a pretzel again provided the valve is free.
Stuart
