The problem with SARCO is, and has always been, that you don't know what you're going to get until you open the box. One guy gets essentially a brand new set, while the next gets a semi beat up bunch of junk---and all for the same price.
Which is why I don't buy anything from SARCO unless it's something I just can't find anyehere else. And let's face it, you can find a bunch of milsurp M16 and M16A1 stuff out there these days; including right here on the Equipment Exchange section of this site.
Once bought a Galil gas piston from them, and got a brand new piece; so when a guy over on the Valmet/Galil site asked about getting one, I shared my experience. He e mailed me a couple of weeks later and told me they'd shipped him a beat up, ususable piston that was in worse shape than the one he was trying to replace.
Yes, I still take my heart in my mouth and order the occasional item that I can't find anywhere else from them, but I learned not to either recommend nor naysay anything from them, 'cause what I got is unlikely to be duplicated on anyone else's order.