For #52, could we try the font that is used in
#6 and
#56? For #60, maybe try the font in #51 and #52, or perhaps even the font in
#6 and
#56 (although I'm not sure whether this will work). It may require some slight tweaking in the symbol, which I think would be fine. Just like you evolved your original symbol from a more 2D format (#31) to a more 3D format (#52), perhaps we could try that for the "mondrian cube" symbol as well?