Yes,the long arm bases are hard to find we need a couple ourselves,I just met a guy & Weaver's auction this yr that brought me 2-29's 1-shortarm & 1-longarm in the back of a horsetrailer they had the heads still on the stands(bad way to haul) & of course they were bouncing arond back there & broke the longarm stand in about 10 pieces.
Oh,well at least the head didn't get hurt.
Customdoug,yes the arm of your machine will be way out on the left side of the stand if you used a treadle base.We usually put them on a standard 20x48" flat top table with one of our DC servo motors w/a builtin speed reducer & they work great.
Bob