I thought about this for quite a while.
In the end I decided that I would start with a fresh copy of LOCSE009.TTF and add new cells to the font, mapped into plane 0, and copy the glyphs. So the font now has two copies of the glyph for each of the symbols for the 65 localizable sentences thus defined.
My reason was that I was unsure as to whether my original approach might lead to problems, so I thought that it was safer to copy the glyphs to new cells, just in case, even though this makes the font larger and might not, in fact, have been necessary.
The font is available from the following post.
William Overington
2 June 2011