The "JL" piece is not straight. That is a cause for concern, although it could mean nothing more than it fell off and was re-soldered on.
However, while the buckle may be an original JLC piece, it is highly unlikely that it would be original to that watch. The "JL" logo started to be used in the late 1950's, while that particular model was sold in the early to mid 1950's.
The time periods don't really match up.