Well, I have some old little utility I had written about 15 years ago that may work for you. Get these two files:
Use:
editfont somefile.fon
It will ask the dimension, press 8 for the 8x8 you need.
Read the screen for help on using it or ask me directly.
The font file created with this utility will contain data for all 256 ASCII codes (0-255) in sequence. Once you save the file, and exit, use the second utility to convert it to a S19 file.
binex somefile.fon somefile.s19 $C000
where $C000 is an optional load address for the S19 file, otherwise it will be zero.
Hope this helps.