[asheshouse]

The size doesn't matter.
You don't have to copy an existing map size.

Start with MWmap_c which is 50m per pixel.
The size can be any multiple of 32 pixels in each direction.
All the others scale from that.

If you like use the Okinawa map for the master files.
Expand all the *.tga files north and east to pick up Kyushu.
The coordinates for the objects (except bridges) will remain the same.
I think the y axis is reversed for bridges (not sure).

Paste in Kyushu *.tga images and your half way there.