A beauty tahunua.
Might want to pull the front sight base spline out of the I slot before you go shootin' or risk losing it on the range. Rub some grease or oil in the I slot to prohibit/slow rusting.
Also, might want to begin a quest for an older Weaver or Lyman scope and rings... just because. Not that it'll be easier to or better to shoot with, just to take it back to warhorse status should you decide to dress it up for re-enactment sake.
But, I'd say your value of that A4 is far far north of $300, by a factor of X8 or X9 at least. Find a period scope/rings, maybe X10 or more to the right buyer someday.
ETA, might also want to look for a C or scant stock as the straight wrist was NOT correct for the A4 as I recall.
Youth rebels, age conserves; between them, they advance. The Marines will cease to win battles the moment either camp achieves ascendancy. – Robert Leckie, Helmet for my Pillow