I know this sounds crazy but I have removed side plates before with an air compressor and a blow gun. I stuck the barrel down inside a sock and blew air between the hammer and frame. If anything should fly apart it will be captured inside the sock. Did this while working on a couple old S&W...
Could have been an over pressure reload. Had a co-worker do this a couple years ago to a newer model Remington 700 in 7mm 08. He took a rubber mallet to the bolt just to break it open. He found out not to trust just anybody that reloads ammo. Gun was fine afterwards other than a couple scuff...
Before you decide to make a wall hanger out of it have a look at the Savage 311. The top rib is designed with a separation in it (not a crack). I have an old model myself with this design. The reason for this is because they solder the barrels to the latch lock. Then they position the barrels to...