I got a 70's wingmaster off of a buddy who said that the blueing was still good to go with no rust/pitting, got it from his uncle years ago. He used it as his cottage crow blaster. It was a 2.75" receiver with a 30" smooth bore barrel and nice walnut stock with police style forend. This deal was about a year in the making. When I finally got it, the outside of the barrel had visible rust on it and same with the receiver. The mag tube's blueing was quite worn down from years of blasting. The stock was so long for my short arms, my arm had to be fully straight just to reach the pump. After seeing all this I dealt him down $25 for a total price of $100. What a steal!!! Once I cleaned it up, it looked infinately better. Still has some minor pitting on the top of the receiver and a couple minor rust spots on the outside of the barrel, blueing at around %60-%75. That sucker was so long, when I'd be running around the house in my underwear with it (obviously when the wife wasn't home), I'd come close to punching holes in the drywall and knocking over vases. I have since put a DA 12.5" barrel, Dlask 1 shot ext (sticks out past the barrel, looking for a cheap 14" to even things up), hogue forend, and speedfeed pistol grip stock with a short LOP. All these parts bought from the EE. All in, it cost me less than $300 for my first build.
Once I can find another cheap receiver, I will have 2 complete 870's. Here's my grand plan:
Riot gun: I'd like to keep this one fairly clean and KISS but still be functional for me, like a hybrid traditional/tactical, with more emphasis towards the old school.
-refinish the walnut stock/forend in a nice blonde tone after cutting about an inch off of it and then learning how to fit and install a grind to fit recoil pad on it.
-12.5" barrel (or 14" barrel if I can find a cheap one) with an XS big dot or the like to lower the POI and crappy DA bead.
-keep the 1 shot ext. if I have a 14" by then
-sand (don't have a sandblaster) and refinish all metal in a matte black duracoat that a buddy has left over. Possibly fill the minor pitting on the receiver with JB weld prior to duracoat (just brainstorming this part)
Tac'd out gun:
-speedfeed pistol grip stock
-cut down the massive 30" barrel to either 18" or 20" myself
-XS big dot
-hogue forend for now, I might go with a cheap blackhawk forend so I can put a rail on it, or maybe a magpul if I can find one for a reasonable price.
-2 or 3 shot extension depending on how long the barrel is
-some sort of light kit that's not going to cost more than the gun
-sand (don't have a sandblaster) and refinish all metal in a matte black duracoat that a buddy has left over.
-duracoat the stock and forend in OD, also left over from a buddy
As you can see, I plan on doing all the work myself, short of installing the sights. The majority of the parts I already have, so the only major expense would be the price of a beat up receiver. Should be a couple good projects for a low price tag. I might even turn a profit if I ever decided to sell either of them, but why would I want to do that?