SUMMARY
The probable cause of failure was an incorrectly loaded shell that resulted in excessive breech pressure. A partial obstruction in the barrel due to fragments of a shell case or wad being lodged in the barrel immediately ahead of the forcing cone is a distinct possibility. This being the case, wave pressure build up would occur.The high breech pressure,combined with the defects in welding, poor metal chemistry, lamination, pitting and rust resulted in the catastrophic failure seen in the pictures.
I'd have to agree with what Roy said...
How much did a Baker SxS sell for when it was new ?
I'm betting the price reflects the quality of the barrels.