The closest match to the SWITLIK pocket flap was from the earliest of the PRITZKER. Both share the same design and construction techniques. The difference being the vertical length.
The original SWITLIK PARACHUTE AND EQUIPMENT CO. M-422 buttons originally used for this build 11/16" rimless buttons. These buttons were diminutive by comparison to the 3/4" diameter rimmed buttons used by most all other USN jackets built.
Two other jacket builders (ARNOFF & L. W. FOSTER) followed Switlik and used these same 11/16" rimless buttons on their late War AN model jackets.