I have TH-K2AT M that have full VHF coverage. I found that 3 diodes are in position as picture. The diode no.1 was blank. It is unlike the USA version.
I try to add diode no.1 and it make Full VHF and also Automatic repeater offset(ARO) is function for USA version.
After try to add diode no.2 then nothing happen.
After try to add diode no.3 it become TH-K4 but it can not Tx or Rx in UHF mode.
So I still find the way to mod it to use ARO as in european version(Market code E).
I think if we have the table about the diodes and market code then we can do it as we want.