Yes it can be straighten, as long as it is not kinked at the bend. To straighten it would cause the kinked portion to become very weak or maybe even split, either way it would ruin the barrel and create an unsafe condition in which the gun should not be fired.

Yes, you can find replacement barrels for your Model 37. Try Gun Parts Corps or Bob Gun Shop. Wish I had the info to post a link, but I don't have it here at this time.