So you literally plan on marching randomly around your house/neighborhood with a drum pad attached to yourself? Interesting but whatever works I guess

I would work on seeing if you can borrow the drum. Most instructors/band directors will allow it, especially if it means you putting in practice time at home. If getting the drum is truly impossible, then I think marching the pad is a fantastic idea. If every kid in my drumline was motivated enough to pratice marching with a pad at home, I'd be a happy instructor. I don't really have any ideas that don't involve welding or at least some serious carpentry.