Personally I have never seen one like this, member Fischer will know for sure though. Leon.
"Always do sober what you said you'd do drunk. That will teach you to keep your mouth shut." Ernest Hemingway
An original Dr. Franke & Co. Ludenscheid, (FCL).
Searching for anything relating to, Anton Boos, 934 Stamm. Kp. Pz. Erz. Abt. 7, 3 Kompanie, Panzer-Regiment 2, 16th Panzer-Division (My father)
Seeing powdery white coating on a zinc badge is Never good....
"Much that once was, is lost. For none now live who remember it."
'I do not think we can hope for any better thing now.
We shall stick it out to the end, but we are getting weaker of course, and the end cannot be far.
It seems a pity, but I do not think I can write more. R. SCOTT.
Last Entry - For God's sake look after our people.'
In memory of Capt. Robert Falcon Scott, Edward Wilson, Henry Bowers, Lawrence Oates and Edgar Evans. South Pole Expedition, 30th March 1912.
This one is a good Franke & Co., Lüdenscheid (FCL) ISA with a crimped in hardware system unique to this maker.
This is also the only FCL variant with a maker mark on the reverse
Condition is worn but with the right price could make for a nice addition.
The white powdery looking substance could be residual finish.
I do agree with Ned, it is definitely not zinc pest.
Best Regards, fischer