Hej Holger!

 HG> That may be all that is needed but if not, I can always include
 HG> the leading byte. Kind of cut and try <BG>.

How about something like this instead;

hex  dec   UTF8    hex      dec
86 | 134 = 00E5 | C3 A5 | 195 165

The above matches the small angstrom.  We could drop the UTF8 codes but I for
one find them handy.  Also I am using IBM437 for PC-8 and near as I can tell
they match perfectly but I'll let you be the judge.  As far as 24 bit
characters those are mostly symbols and line drawing characters from what I
see, and it looks like all the text characters are 16 bit and the leading byte
is C3 (195).  For the degree symbol found at the end of temperatures I get a 16
 bit character except with a C2 (194) as the leading byte;

F8 | 248 = 00B0 | C2 B0 | 194 176

I'll wait until hearing back from you before taking this any further.

 HG> I don't need more than 16-bit characters for that editor.

Other than the occasional Euro sign I suspect so.

Livet är gott,
Maurice

... Gråt inte för mig jag har vi.
--- GNU bash, version 5.0.2(1)-release (aarch64-raspi3b+-linux-gnu)
 * Origin: Little Mikey's EuroPoint - Ladysmith BC, Canada (2:280/464.113)