I looked in the 1949-1959 Ford Parts Text Catalog. The only thing close to your number was a listing for a FEW 12127 number with the suffix of 'H'. FEW 12127-H The listing is for a '59 Thunderbird with the 430 engine.
IF I'm understanding the listing, The FEW 12127-H was an early '59 production application, superseded by a distributor with the distributor housing stamping I.D. of B9MF 12127-B. In the description column, the B9MF 12127-B distributor has the notation, 'pivot plate type'.
In the 1960-1964 Ford Parts Text Catalog, the B9MF 12127-B is again listed for the 1960 Thunderbird with the 430 engine along with the notation 'replaced by' B9MZ 12127-B
Someone more knowledgeable about the Ford numbering system may be able to explain the suffix variation for you... I hope!
NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York