Does Tapco include a set of rails with every flat, or do you have to order them seperatly?

www.tapco.com/product_information.asp?number=AK0669&back=yes&dept=214&last=214

Rails are shown in the pic but it doesn't say they are included.

I believe the rails are included. My flats came with rails.

How hard is it to install the rails?

The lower rails are not that bad to put in. After I get the Tapco flat folded up, the lower rails get the long solid rivet with center support bushing put through the corresponding holes in the rails. The flat side of the rivet now protruding through the receiver gets mushroomed 'til the head formed.

Put front trunnion in there like it was going to be riveted. Line up the fronts of the two lower bolt guide rails with the lower part of the bolt guides cut into the trunnion. This when I clamp 'em in place, remove the front trunnion, then MIG weld a few places on the underside of the rails to the receiver.

The center support rivet keeps rails from sliding back and forth, the MIG welds keep rails from pivoting up and down, (or any movement for that matter).  

Another way is to buy a spot welder, or TIG welding the underside of the rails would even look good.

I had been wondering if I could use my wire welder on the rails. Does it hold as good as spot welding