I have a 3 position collapsable stock that appears to be all metal, reciever extension as well as sliding part (aluminum ?). There are no markings on it other than a "B" on one side of the movable part. Does anyone know anything about this, such as who made it and is it considered to be good quality?

Thanks.

I'd guess Bushmaster...

I believe some of the older Colt colpasables were amuminum, my firearms instructor has had one for years.  From my experience, you can pay $90 for a "Colt" stock that does not say Colt or what looks like the same damn thing for $40.  The dealers at gun shows around here always mention "well this is a Colt stock" yet it does not say Colt anywhere on it.  I have one of the platic "Colt" stocks and an off brand plastic stocks and can't tell the difference.  Seems like a bunch of hype to me.  Some folks believe that the amuminum types better, I prefer plastic since it is more forgiving when it's smacked.

Agreed.

I have a "Cherokee" cheekpiece on one of my HBARs that is the non-branded version of the cheeckpiece that Colt used on their Delta HBAR.

I think mine was $35 and the Colt version was $80-and they are the exact same thing.

Colt "sliders" of the later mfg. have an "N" under the slider latch lever, they are phisically different in very minor way, but you gotta see them side by side to notice the differences......  

I'd guess Olympic Arms.