Want to Buy WTB: Little red button for a Leica M3

I was shooting my grandkids with my M3 on Sunday......when I get home, I notice that the little red button that goes in the middle of the ISO dial on the back door of the M3.

Does anybody know where I can get a replacement? i know that it is not that important, but I am pretty picky about my cameras.

Any help?

Thanks

J Durr

I'd try DAG camera, he does sell parts

Good idea....thanks John

Try Leica USA - I hear they often give them away

Thanks to all...Leica USA is sending me one!