Afraid you won't. If the stray brain cells I have left are working, that was made by Harrington and Richardson, and shares parts with the 1900 model. I checked over at the Numrich site, and while they have a few parts for your 100 yr old shotgun (plus or minus a few years) they are sold out of stocks and forearms. Sorry, bro. Short of finding an organ donor gun sitting in the pile in the corner of an old time smith......
What we have here is... failure- to communicate.