To bump a two year old thread....
Since the last post, has there been any improvement in the availability of lowers? As others have noted the uppers are cheap and still readily available but NOBODY seems to be manufacturing the lowers. Even Dorman doesn't have anything and my local parts shop has been waiting over a year for anything equivalent. I'm still waiting on the backorder for something OTHER than RareParts.
That being said, the RareParts replacement is now
$170CAD after taxes and shipping for one, and I need two of them. Separating the bracket off a failed lower and trying to bolt in a brand new upper in its place (the bolt holes DO line up but you have to saw the bottom indent off the bracket) has likewise found the upper has a narrower taper and a longer thread, so that isn't useable in case people were curious.