Motorizing a Madsen

One possibility--get another pair of (steel) forks, spread them wide enough to accept a rear hub, then put a rear 26" wheel in and do a front-wheel-drive setup. {make a engine-mount bracket so the normally-rear-mounted engine rides above the front wheel, in front of the head tube}

With a cargo-bike setup you would probably want to get the engine gearing way down lower than usual.
~

I was about to go and ask this question myself, but I figured I'd see if someone else had considered it as well...

If you're still thinking about this, I'd say go for it. I'm a huge fan of Madsen just for how cool I think their bikes are, so making a Madsen into a MB would be quite something.