I am sorry I have no G&U, and I will very probably never have one.
Now, the G&U were made back in the very late 1950s and early 1960s, more than 50 years ago, and were made by skilled craftsmen. Nowadays, Ubertis are machine made, under computer control. The resulting product just cannot be the same.
Here is a picture of the Gregorelli workshop back in the days. I believe parts made and adjusted this way cannot be interchangeable with parts made today.