I don't know anything about Gios and Cinelli ever being one company and splitting. Not saying it didn't happen, just that I never heard about it. Not too surprising since I don't follow the European steel frame market all that much. What I do know from personal experience is that besides stems and bars Cinelli was famous for its investment cast steel bike frame components, lugs, fork crowns, dropouts, seat stay ends and (Ta-Dah!) bottom brackets. If the bottom bracket is embossed Cinelli on the bottom, it is likely because it was one of those. And probably (not certainly by any means) the lugs and perhaps the fork crown is also Cinelli. One design that was very popular in Cinelli fork crowns was the fully sloping one. If the Gios bike has one of those, you will recognize it immediately. Fully inserted into the fork blades with no lug-like structures on the outside of the blades. I doubt there was ever any true advantage (strength, stiffness, durability, etc.) to having a steel bike built with that brand frame components, but at the time, it was thought so and was considered very prestigious.

You can find pictures of all this stuff here: http://www.classicrendezvous.com/Ita..._frm_parts.htm. Click on the pictures for more examples and detail.