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Thiers Issard still make them https://www.theinvisibleedge.co.uk/strops/255-ti-b-strop-double-sided-box-strop.html looks pretty nice.

I agree, I think that it's maybe a travel strop with razor storage built in. Time will tell.
I had a similar experience with some fountain pen ink from the U.S. I placed a bid just so I could keep...