Dimensions for JED's GH6-574MHz "Narrowband" Antenna [Tuned for 575 MHz = Ch31] are found here:
Hoverman HDTV UHF antenna
As described by JED, nearly ANY Antenna can be RESCALED for Operation in another Band by changing ALL of the Dimensions [incl. Wire Size] by:
Rescale Factor = F = Current Design Frequency / New Design Frequency
Hence F = 575/536 = 1.07276 [All Dimensions are LARGER....as you calculated above]
So JED's a = 9-7/16 inches would be Rescaled to 10-1/4 inches.
BTW: The Zig-Zag Angles are NOT "square".
Since the difference is small, the SAME Wire Size can be used with negligible change to Gain and SWR.
Note that although JED provided all of the OTHER 4nec2 Files, he FORGOT to include the 4nec2 File for the Narrowband G-H. If you NEED it to say view ALL of the Dimensions, I should be able to regenerate it without TOO much difficulty.....Let me know.....
Unless you are using a Design Optimization Tool, such as nikiml's Python Optimization Scripts, I do NOT recommend changing ANYTHING in the posted Design Dimensions.....it can quickly turn to MUSH.....and BTW: why would you even WANT to change anything????
FYI: For comparison purposes, it would take a [much simpler to build] 15-El FD-Yagi to provide same 16+ dBi Gain, using K7MEM type design [which means I SHOULD be able to match that with an OPTIMIZED 14-El FLF-Yagi (Flat-Loop-Fed) such as my 9-El FLF-Yagi]: