I have my HC machine sitting right on top of my treadle machine ..... kinda dumb I guess, but it's handy there.
If you want a truly portable H C machine hunt up a Singer 99K-10. Very rareum, only made one year back in the 20s. It's made from aluminum.
Or, hunt up a Sewmor 303 or 505, they are also 3/4 size aluminum machines. That would make a dandy HC.
Joe