I haven't gone over the whole frame yet, but I figured there were a few considerations that I would have to take into account with this project. I've done my homework on the MANY Sachs engines out there. It's tough, my buddy actually has a semi-junker Foxi GT deluxe WITH the 5041A engine.
The tank is BEYOND repair inside, it runs okay, but he has two really nice other peds and wants to get rid of the Foxi. He needs it, though in a trade with another friend first. Which makes sense. But if that doesn't go through, I'm ALL OVER that bike.
Until then...I'm going to keep searching the net and this site for engines.