Model 44 help

[Civi'sOutfitters]

Hi, I am helping my Uncle with heirloom shotgun he has (Marlin Model 44). He told me that the weapon originally become stuck in the open position during a rabbit hunting trip back in 1994. He had a armorer get it to slide shut but did not explain the issue, now it will not load, eject or open. I recently became a gunsmith and do not have much experience with this model. Is this a common issues with this model? My google-fu has turned up nothing, but I did luckily stumble across this form. I also can not seem to find a diagram or parts list for the weapon. I live two states over from my uncle and do not have the weapon in front of me. I wanted to get my ducks in a row before I have him send it to me. I appreciate any help any one can offer.

[Regnier (gunrunner)]

Civi'sOutfitters;

IN this case, it might behove you to get your hands on a copy of Bill Brophy's book on "Marlin Firearms, A History of the Guns and the Company that made them." On pages 396, 397 and 398, you will find some help with a parts breakdown along with a photo of the breech bolt release to open the action.
You can go to the Numrich Gun Parts website and view a parts diagram with parts listing.