I made an AOB Wheel mod for SH4, which must be somewhere...
To calculate the distance, you first determined the AOB.. turned the wheel to this AOB and then measured the length of the ship resulting in the range. You required only 2 measurements to get approximate speed, range and range at aob=90. Measuring the length of the ship, is more accurate than measuring the mast height unless the AOB is around 180 or 0, then it's a mast height measurement.
To convert this mod to SH3, someone must measure the lengths of all the ships and plug those values onto the board.