Yes, High Standard makes ARs. I know this because at the last Big-Freakin'-Huge gunshow I got to, High Standard had a booth there... Only two items on display were AR-15s.
I handled one of them... 20" A2, nice rifle... couldn't tell it from any of the others once I was behind the sights... But... Frankly, I'd go with a known brand.
I'm also not sure just what barrel it had... Chrome Lined or just Chrome Moly... And not sure about the rifling [1:9 or 1:7]... Also didn't get a look at the guts, so I really don't consider the 15 seconds I took looking at it being enough to say if it's a good rifle or not.
Funny... I don't remember anything about the second AR on the table... All I remember is that it was also an AR and also a High Standard... Might have been an A4... or a carbine... or both... don't remember.
Funny note: I asked the guy what the MSRP was... I don't know who he was, but he acted like someone with rank... Hell, might have been the owner... he just kinda stared blankly... atempted to process my request, had a brain FTF, and said: "I........ don't know............ I honestly don't remember what we sell them for."