Remington Model 31 12 gauge Parts

Here’s the story:

I inherited this shotgun from my grandfather in 1995. Used it for a few years before shipping off for basic training in 1997. I was cleaning my guns before leaving as I anticipated I would be gone for quite a while. It’s been a minute but I remember losing a spring in the carpet and I couldn’t find it to put the barrel back on. I collected the parts and put them in a Copenhagen can and put them on the shelf thinking I would find a new spring when I returned home. My mom had other plans and when she saw a random Copenhagen can in my room she decided it would go in the trash not knowing what was in it. So that’s how the parts went missing. I still have the shotgun and have always wanted to repair it as it has great sentimental value and it’s cool. 

I have attached a photo of the barrel and magazine tube where it attaches. I based on the stamps it was manufactured 10/38. I know there were changes to this part in 1943 and that’s where my heartache has been finding parts.  Plenty of post 43 but very few pre 43 parts out there. 

I do t know what parts I need to get this back together so if anyone is familiar and could give me a list I would forever be in your debt.