I can't ans. all your questions, but I can give you the following information.
There are several models of this rifle, so to provide you with what infromation I have I will address each one.
M-14: (NORINCO PARTS).308, 20 shot mag, newly mfg. M-14 using Norinco parts wood stock mfg 1991-92 only: @100%=$600.00
If I am not mistaken this was distributed by KYENG (KING) of Atlanta, (College Park GA)
M-14 (USGI Parts)(United States Gov. Issue) .308 cal. 10,(C/B 1994) or 20 shot mag. newly manufactured M-14 using original excellent condition forged G.I. Pars including USGI fiberglass stock with rubber recoil pad. New 1986 @NEW=$1,550.00, @100%=$1,225.00.
M-14 BEGINNING NATIONAL MATCH:mfg from hand selected older USGI parts, except for new receiver and new USGI air gauged premium barrel, garanteed to shoot 1 1/4" group at 100 yds. New 1993: NEW=$1,950.00 @100%=$1,625.00
M-14 NATIONAL MATCH: Built in accordance with U>S>A>M>T>U> mil. specs. 3 different barrel weights to choose from, national match rear sight system, calibrated mag, leather sling guaranteed 1"MOA New 1987
NEW=$2,295.00 @100% $1,950.00.
I hope I have ansd. some of your questions. I am only vaugley familiar with the US (UNITED STATES)A (ARMY) M (MARKSMANSHIP U (UNIT) PIECE. AND WILL SAY THIS ABOUT THAT. I know the man who was instrumental in designing the original M-14 National Match for the Army and it was well built and accurate. If I were to buy one, the USAMTU would be my choice.
I am not positive about this, but as I recall, wasn't this company originated in Columbus, GA.
[This message has been edited by Harley Nolden (edited May 10, 1999).]