My mudflap ripped too and I just bought a sturdy square truck mudflap and
lined it up with the edge of the old one, and sandwiched the new rubber
between the two metal pieces with new bolts.  I used an exacto knife to cut
away some rubber to make it a nice flat area to attach to.  It looks great
and works better than new since I let it be a bit longer.

If I bought a new propane tank, I would figure out some way to attach a
removable plastic cover to the front as that seems to be where all the snow
and crap accumulates.