DPMS AR 15 22LR Dedicated Upper

I took this as a partial trade and I can’t seem to even find a picture of this configuration anywhere. The pics and info that I find are all with the forward assist, ejection port door and Shell deflector and have the 16” Bull Barrel in black but not Stainless Steel as you can see mine is a Slick Side receiver and SS Barrel I know these were discontinued but don’t know when. I know those mags are impossible to find 2 are Colt and the other is No name and if you find them they are very expensive. Does anyone have any knowledge of these like Value, when they were made in this configuration if at all or maybe this is not the original receiver, can I remove the barrel and bolt and install my 5.56 barrel and bolt or were they made proprietary to 22 I just disassembled a 5.56 and turned it into a dedicated 22LR. Thanks in advance Keith

Can’t help on dates/values (search gunbroker?).

As for possible 5.56/223 compatibility with a new barrel - For a starting point get a 5.56 bolt and see if it will slide into the upper? Does the receiver have bullet tip channels that would line up with a 5.56 barrel?

Is there an opening in the receiver above the barrel for a gas tube?

I have a 5.56 Bolt and Barrel because I disassembled one of my 5.56 “Others” and turned it into a dedicated 22 with a CMMG Bolt and Barrel a couple of days before I found out I was getting the DPMS and the Upper is due here Monday. Any info I can get on this Upper says that these uppers are very good so I may just keep it the way it is I know the original Mags are scarce and impossible to get. Here’s a pic of the 22 I Built

Black Dog Machine makes a wide range of .22LR mags for various AR uppers, even the old Bushmaster!

DPMS stop production on these uppers in 2004 you rarely see them come up for sale I’ve seen the mags on Gunbroker for over $100 anyone have an Idea what this is worth as a complete 22 upper or what the components are worth individually if I was willing to separate it