http://doubleredseadweller.com/5513maxi.htm
this page shows 8 mil with matte dial type V
The Type V is the very last style of matte 5513 dial usually found in watches from the late 7 to 8mil+ SN range, immediately before the change to gloss/WG surround dials. For the first time in non-date Sub history, SUBMARINER is printed wider than the depth rating, a characteristic that Rolex would make permanent with its glossy successors:"
i have almost no experience with vintage but this does seems to show possibility?