Scooper

EDIT -bertinjim beat me to it.

Nervex was a French manufacturer of lugs, bottom bracket shells, fork crowns, and dropouts, and these parts were used by many frame builders, big and small, all over the world. The parts were high quality, but the builder's skills are far more important and ranged from the best builders in the world to amateurs who often made mistakes like overheating or underheating while brazing, leaving significant voids in brazed joints, etc. With a frame that has no decals, serial numbers, or distinctive construction details, I don't think you're going to have much luck Identifying who built it.

The numbers on the BB shell are angles, tubing size (French or English), chainstay dimensions and spacing, etc.