Don't forget that original DM was designed for 320x200. As DSB runs in a "doubled" window, you might expect that to be 600x400, but it's not, it's 640x480 -- so there's an additional 80 pixels of black space that never gets used.
For my own re-design of DMs interface, I've made that extra space a feature and have re-designed everything to use it all
By the way, I like the style you've chosen for your game. Very unusual and distinctive. You definitely have a unique flavour here and I'm intrigued to see more.