It was exactly as you all advised with the firing pins in the fired position it made it extremely hard pressure to put it back on. With the help of my dad we tried the push hard method and it clicked back on. It was a frightening amount of force to put onto a 100 plus year old gun but as stated it did clip back on with no damage.

A very scary learning experience, thought I had broken my families favorite shotgun.

Thank you all for the help