Nice score!
Check the BB threads when it arrives. They probably Swiss threads.
I've got a GJ about '74 vintage. It's got a Stronglight 49 crankset, Huret Jubilee gearchangers, Weinmann centerpulls. Mine came with 27" wheels (Normandy hubs with Weinmann rims)...not sure if the wheels were original. I've since put 700c on it.
I think the GJ was a very good mid-range bike, probably under-rated in it's day.