Hello all, and thanks for the advices.
The frame result to be a later manufacture of the Designer 84' (after long research) given the absence of the seatstays pantograph.
Given im not able to post links because I'm newbie, find below the link to the final look of the frame. (you need to delete the 5 spaces between to see the link propperly)
Let me know your thougts!

htt ps://dr ive.go ogle.c om/file/d/ 1djINd4DZGkTgbryZyH-pvr9MM16eTUj-/view?usp=sharing