No software's been written for it - I tried, and just don't have the knowledge.

I can put together something using one of the obvious drawing algorithms and playing tag back and forth with you testing it.. For anything more complicated I would definitely need one to work with.

Kind of defeats the purpose Maybe the best laid Plans of Mice and Men can not full in my order

Are you sure you can't use one of the VFDs? They're available in a wide range of sizes, from bigger than the Empeg's (the one I'm using) to really tiny (the one foxtrot's using).. you could put the tiny one almost anywhere (in your instrument cluster perhaps), it's something like the size of a pack of gum. Something like what I've done can easily be done for < $500.