Did Egypt re-barrel any of their FN 49’s in 7 mm Mauser?

[KneverKnew]

A local gun store has an Egyptian FN 49 for sale. They have it labeled 7 x 57. When I asked if this was an error, they said no, that Egypt had re-barreled a large number of their FN 49’s after the war. I have never heard of such a thing. Does anyone else know of this happening, and if this is possibly a legitimate rifle? They are asking $800. The rifle looks well used and worn, but the bore is in fairly good shape.