colt or springfield? and will either work on the others gun. what sa describes as a polished blue, is that the same as colts royal blue? hate to sound dumb but i've never used either. gonna send my gi to sa for the defense package and a few other things and i've never sent my original series 70 to colt for the lower and flare and refinish. if sa's looks like royal blue i'll send them both there. also, visually whats the difference between hand and machine cut checkering.