Ariel,
Actually, the crusaders did do a well documented raid in the Red Sea in 1182-83.
https://www.jstor.org/stable/40000370
But, even though there were crusader battle trophies in Eqyptian museums, I agree the crusader connection to the kaskara is likely a Victorian marketing ploy.
The mechanical jammed wooden attachment of the kaskara's blade to the cross guard seems to me to be an innovation to the Mamluk method.
The Sennar (chisel) ends on some cross guards is a kaskara innovation over the rhomboid, as is the welded four part method of fabricating the overall cross guard. Unlike the cast cross guard preferred by the Mamluks.
Regards,
Ed