bingo.
- copied english.geo (and englishuk.geo) to my xcom/geodata folder, renamed them to lang1.dat (and lang2.dat) and let BB's toolkit 'convmisc' turn them to .Gifs. Edit*. 'convmisc' them back to .Dat files, then copy them back into oxc/Language and rename them back to english.geo (& englishuk.geo)
* then save Gif as type87a ( non interlaced )
presenting, 0xC w/ modified Geoscape panel