SHAPLEIGH HDW CO DE B19 Medium double MOP switchblade knife w etch

Vintage SHAPLEIGH HDW CO DE B19 Medium double MOP switchblade w some etch made by Schrade Cutlery Co of Walden, NY sometime between 1916 and 1946. The Shapleigh catalog number for this knife was B19 and it measures 3 3/8" closed and 7 1/8 inches open with nickel silver liners buttons and safeties. It is a Spear/pen blade combo and the blades are both 98% full or better with some of the original finish and original blade etch that reads "Diamond Edge" with a diamond between the words and the letters DE inside, though the etch is faint, you can read it, but it's faint and nearly impossible to photograph. The tang of the large blade is stamped SHAPLEIGH HDW CO around a diamond with letters DE inside. Small blade is stamped US PATS DEC 21, 09, SEPT 13, 10 and JUNE 6, 16. The original Mother of Pearl scales (handles) are in good condition with beautiful luster, but each scale has a hairline crack as you can see in the pics. The knife works well with both blade tips below liners closed, both open fully with very good lockup open. Small blade has kickback (blade opens too fast to lock so bounces back). No rattle if shaken with the blades open. Both safeties work. VG+ condition.