I'm not really interested in a design, just want to be able to generate public and private keys offline, just like VIA, BTC, ...
You can already..just use a universal paper wallet generator
http://cryptolife.net/upwg/Just looking at this... but can't quite work it out. How do you know which decimal value to use? According to the chart for addresses starting with uppercase "D" it's 29, 30, 31 or 32....