Wide ring on the back

Early 527s do not say Germany on them.

Checkered handles on the combination plier.

No text on the screwdrivers. Small screwdriver with smooth neck.

Early 772/2 also don´t say Germany.

Screwdrivers with yellow handle tips.

764 tube length is about 112mm, handle is longer. Also notice the round box lid clip.

764 is stamped "DRGM", Deutsches Reichs-GebrauchsMuster.