Sounds like there might be an interesting story behind the bent cantilever, would you mind sharing it?
I suspect the cantilever mounting arm is in fact steel. Magnesium has little ductility and tends to fracture when deformed by a significant amount. I had an Ithaca aftermarket slug barrel that broke the solder weld when I was sighting it in. Ithaca had gone under and I could not get the store to do an exchange since it was past 3 months when I had purchased it. Anyways, a smith friend of mine was able to re-solder the arm to the barrel and it has since proven to be a good shooter.
You'll likely need to send it back to Remy since the cantliever arms do not seem to be a common replacement item. A bit more tricky would be to have a trusted smith work on it and try to rebend the arm but it could be an issue getting the alignment set properly. Depending on price for repair, you may just want to get a new barrel.
