Good, it is unmolested.
recessed mountings started to appear 1973, very infrequent- I will even call it "one off".
I first saw it on artisan American builder bikes.

circling back to Masi, there was a trade show bike with recessed brake attachment in 1975.
then nada till years later.

Confente used recessed attachment in 1976 as standard. Still very early.