Years ago, fake/counterfeit parts such as carburetors, distributors, etc., for '71-73s was not a big problem. Everyone was so busy hating on the '71-73 and Mustang II's that no one gave a second thought to wasting any time counterfeiting parts for these outcasts. The big money was those types of parts for any K code engine, Boss 302, 429, 428 CJ/SCJ. But now that most of those vehicles are in the collector's hands, they finally figured out that the '71 429 and Boss 351s are now bringing big money and worth a second look. We've all seen the NOS $8,500.00 Boss carburetor and $1,200.00/ distributors. As far as the fake part shysters are concerned, the bull eye target has now moved to our butt cheeks!
I commend you for wanting to verify the authenticity of the distributor you have. If your distributor is a production-installed (OE) unit, the housing should be branded Autolite and have a cast "12127" with a stamped "D1ZF-DA". There would also be a date stamp below the 12127 indicating the actual date of manufacture. Typically, there would be on average, a 3-month time frame before the vehicle's production date. Lots of variances on the assembly line, so that is not set in stone.
Since Ford was transitioning to Motorcraft in '72, any service replacement distributors sold after the Autolite stock was depleted would be branded Motorcraft. Most of those I have seen would have the "D1ZF-DA" stamping but no production date. Eventually, Ford stopped stamping the housing and started using a metal tag much like the ones used on carburetors that everyone liked to throw away. One of the vacuum advance screws fastened this tag to the distributor. The production installed vacuum advance was the "Banded style," although it's debatable how many of those are still in use. The service replacement vacuum advance and those on later service distributors were the "Crimped" style.
The distributor housing for all 351C engines was sourced from the '68 460 Mark III Lincoln, so all will have a Lincoln C8VF-12131-B casting number on the housing. The bare housing never had a service part number assigned to it and was never available separately. So that number cannot be used to definitively ID a Boss distributor.
This is probably a little more than you asked for, but hopefully, there is some helpful info you can use to ID your distributor!