Intriguing! Clearly naval in origin (naval crown, use of rope and navy-blue background). What draws together an Allied Navy, the British Combined Operations badge and a snail, during or shortly after WW2? I’ve seen nothing like it before and could find nothing on the Internet. It’s likely a locally made, unofficial, badge which will be very difficult, if not impossible, to trace.
However, it’s interesting to note that in 1975 the Royal Australian Navy (RAN) used a derivative of the British Combined Operations badge for their landing craft squadrons described below.
"RAN Amphibious Squadron Insignia The first official use of squadron insignia for RAN amphibious vessels was instituted c.1975 when landing craft of the First Australian Heavy Landing Craft Squadron (AUSLANCRON ONE) adopted a derivative of the British combined operations badge as its motif. The badge was affixed to the funnels of the Balikpapan class landing craft heavy and later to the heavy lift ship HMAS Tobruk (II). The device comprised a navy-blue field with a naval crown above an anchor, superimposed with crossed swords and a kangaroo ‘in flight’ all picked out in red."
Staying with the RAN, but going back to the post war period "HMAS Kimbla, a boom defence vessel commissioned on 26 March 1956, had the distinction of being the last vessel in the RAN to use a reciprocating steam engine as a form of propulsion. Capable of achieving only 10 knots she was affectionately dubbed the ‘snail’ and it was this motif that she adopted as her distinctive funnel insignia during her twilight years. Kimbla decommissioned on 15 February 1985 having steamed an arduous 363,038 nautical miles.”
Was there a precedent to draw on when they adopted the snail in the 1970/80s? It’s a tenuous link but perhaps worth being aware of in the background.