On the rails all you need to do is heat treat the ejector part of the rail I have 1,500+ rounds on more than one I have built just heat treating the ejector part of the rail. Plus when you assemble it and fit the bolt you will need to file the ejector for the bolt to clear which will require it to be heat treated again.
Also heat treating the rails is hard on the drills, reamers, and files always best to do it after installed and every thing is fit just perfect.
You must have used Tapco for the rails to be pre-drilled these are ak-builder which are the Cadillac of build products.
I am In Vancouver..
I have done a lot of buisness with Curtis. All my tooling came from him. He has aircraft quality tooling. As far as flats go, flats are flats. There is not a whole lot of difference when punching out a flat piece of metal. There are a lot more flats out there that are not Tapco that have the rail holes already drilled. A ton of generic ones that have no name. That's cool...to each there own. I did not mean to get into a discussion about flats. I am sorry if this strayed from your add. Thanx for the info.
dude...you need to read up on the laws on home built receivers......what you have here is a felony and I suggest you remove this ad....
once the receiver is bent its your...cannot be sold unless you serialize them with a number, city and state of manufacture, and manufacturing companies name..at which point it must be transfered through an FFL to the buyer. same goes for a built ak on a home made receiver.
Please be aware of the laws regarding these type of things if you intend to partake in them.