I hae a gap here.  I just put the mast pipe in a little hole in the ground
and tied it to the edge of the rooff.  The one I have uses a loopp at the
bottom as the ground and this also helps tune 40 meters.  I don't think
they're particulary difficult to assemble, but you'll sure need sighted
help.  Mine works reasonably well.  If you get the one that doesn't have
the counterpoise on the gottom, you'll need some kind of radial system.
73s
Butch Bussen
wa0vjr