While this specific can does have a flat top lid, and appears in original can condition, it is this author's opinion that not truly a National Colt 45 flat top. Looking closely at this only known Detroit flat top example, there are a number of signs that indicate not a real Colt 45 flat:
It is this author's opinion that the Colt 45 body/label had a design change, and unused printed Colt 45 sheets were repainted and reused for another brewery/label that was still producing cans as flats.
- Along the seam and both top and bottom lids there is red paint, appearing to be remnants of a paintover that has been rubbed out
- The mandatory on the seam is not correct vintage. If truly a flat, the mandatory should state "The National Brewing Co. Of Mich., Detroit Mich", not the newer zip/tab style mandatory
- The newer style American canning company symbol. If flat top, it should have a Keglined oval symbol