The other dimensions are pretty close.
The thickness of the Tuttle fin head is 0.620" -0.624"/15.748-15.8496 mm on the original Larry Tuttle drawing (which I am not at liberty to divulge)
The Skoter dwg. needs to be corrected.
The length of the base (at the fin root) is 6.136"-6.140"/155.8544-155.956 mm.
Larry Tuttle measured the upper corners in a different way than on the Skoter Dwg.
The vertical dimension (from the base of the fin head) to the sharp junction at the back end of the fin is 1.250"/31.75 mm.
The vertical dimension from the base to the sharp junction at the front of the fin base is
Both the top corners get a 0.25" radius from the sharp junctions.
The front and rear angles on the Larry Tuttle drawing are 80 deg. from the base at the wider root side. This is 10 deg. off perpendicular.
The distance between the drilling for the brass barrel nuts is 4.135"-4.140"/105.029-105.156 mm (centered on the top of the fin base). On the deep Tuttle the hole of the shorter end of the fin base is 0.491"/12.4714 mm from the junction of the rear angle and the top angle.
The center of the barrel nut cross drillings is 0.50"/12.7 mm below the top surface of the fin root.
If you modify the Skoter Dwg. with these numbers you will have your own version of the original Larry Tuttle design.
The Deep Tuttle uses all the same widths and angles, it's just 18 mm/0.7086 taller than the std. Tuttle.
If you make your own drawing and send me a copy (not of the forums please) I will check it against the original Tuttle design and make corrections as required.
Best I can do and still maintain my credibility with both Starboard and Larry Tuttle.