I picked mine up from my FFL on Monday, so I'll share some answers.
Receiver is a Morrissey. You can search and find some details on them, made on the same stamping dies and out of the same metal as NDS. Markings are on the front bottom of the receiver. Certainly looks nicer than my old Global Trades receivers from the early 2000s.
Haven't detail stripped it yet, but the trunnion and safety are matching numbers, so I would guess the rest would as well. The Romanians don't traditionally get too wild with stamping serial numbers on everything, I have an old AIMS-74 carrier in a SAR-2 that's unmarked. The kits I've seen available have all been matching numbers though.
No info on the barrel though. AK Builder and Arms of America both have 4150 Nitrided 5.45 barrels for sale, but they are pretty tight-lipped about the source, and there's no details that Atlantic uses the same one. Thread on AK Files did report pretty good accuracy out of the one in Atlantic's AIMS-74 clone though.
Hopefully I'll get out to shoot it soon, but overall, I'm very impressed with the quality of the rifle. No cant, rivets are nicely formed, finish looks great. My FFL was extremely impressed with it as they were logging it in and 4473'ing me out.
I missed out on the first batch, so I jumped on the second batch when I could. My personal collector interest in AKs tends to gravitate towards the Romanian variants, and this is an excellent and rare opportunity to own an AIMS-74/PA md. 86 clone at a very fair price.