I have a complete 16" A2 postban upper -- no muzzle brake, no threads -- for sale. I don't believe the barrel is chrome-lined. I bought this several years ago and got it from either Model-1 Sales, or JT Distributing, I don't remember which. It's got the standard handguards, and I've only put about 150-200 rounds through it, if that. I'm only selling because I need the funds for another project. $300 shipped. Email me at firstname.lastname@example.org if you want it, or if you have any questions.
Edited to add: I also have 2 RRA A2 buttstocks that are complete with buffer/spring/screws. Look to be in excellent condition. Let me know if anyone wants these. $45 shipped/buttstock.