A number of Campy groups came with a gray ano finish. It was called Century. With some pics I am a sure a number of folks here could identify the parts.
Do you have the full line up for the 1991 tour for Z? I am pretty sure that these Calfees were made for the the tour team but less sure the bike was Arroyo's. I am pretty sure it is a tour riders'.
I have another sweet Tour bike that is in partial condition. I will enter it next year. Great bike. Great rider. Almost done. Now where can I find some NOS white Benotto tape!
This is Miguel Arroyo's Team Z Calfee. Lemond ordered 18 bikes from Craig Calfee for his team and this is one them, original down to the bar tape, Chorus crank bolts and Chorus fd. It fits me too!
I figured the OP was posting about the M95x series, which, during the years offered, was available in lighter and darker variants. There may have been three, but definitely at least two.
If I had a full 50th group but was missing one dust cover, I wouldn't be too concerned about 80 pounds for that piece. If it is the first part of a group, seems a lot dummer.
Seems pretty clear that it is a rebadged Attitude. That said, why the fuss, seems like you are spending the time to make the bike your own so it isn't like the goal is to build up a pristine/original Adroit. I'd recommend not swimming against the current and enjoying the bike you have.
Perhaps it goes without saying but use lots of cutting fluid, low spring presssure and cut slowly. You want the chamfered face to be no more than 2.5mm.