Stevens Model 520/620 parts help

[newdumdum9825]

So as I was cleaning my granddaddys 50+ yr old 20ga pump so I can take out to go squirrel hunting with my girlfriends dad Tuesday....... I lost a rather important screw, and when I say important I mean its basically a scrap pile/mantel piece now ....

So is there anywhere I can possibly find parts or even something that'll hold till I find it or am I SOL?

I mean yeah I could use my 410 but it's kinda special an important to me to use my granddads shotgun for my firt hunting trip

 

[1911 nut]

Try here-520. Accessories | Numrich Gun Parts

 

[newdumdum9825]

Thanks! I couldn't remember the name of the site, sadly my firing pin stop pin is broken in 2, but its such a snug fit it isn't a big prob, but the stop pins on the 20ga are sold out