Farmhand Loader Question

Hello,
I have a 1951 H, w/ what I beleive to be an old Farmhand loader. The problem is that it leaks fluid pretty bad from the seals between the pistion or ram (which is approx 4' long) and the cylinder. I have tightened down the cinch nut or whatever it's called, and that worked for a while, and now it leaks as soon as I raise the loader. I cannot find a part or serial number on it, where should I look?

Also, does anyone know what is invloved in replacing the seals and where to find them? As old as it is, might just be some packing material in there?

Thanks for your help,
BGuff