SeattleMD, My 2 cents: Te dark, fairly indistinct lines you refer to, I believe are fingerprints. they are found on a lot of coins. The die cracks on the cornice, and base of the memorial building are caused by stress in those areas. The '83 was famous for having had so many. There is no premium for them, but they do make nice curiosity items. FYI, the
State Quarter series havs a very consistant appearance of a die crack that will at times run from the rim, below, and left of the left end of the bust, then will run across the base to the pony-tial. others will even drop down to the rim, again They lend themselves to a series of progresson views.
Dick