Thanks HiBall, the packing nut for the main ram was loose, I also slightly tightened the nut on the pump plunger until it was clearly firm in the bore. I added a little permatex #3 to the mating surface of the bottom plunger bore nut. I added fluid until i could jack it to full height, and lowered each time standing on the lift pad. I left it overnight and no drip or leak. I will lift the car a few times today and recheck.
I had replaced the ram plunger leather & packing 4-5 years ago along with the pump plunger. The main weakness in these models it seems (long term) is the pump roller in the handle seizes then wears then puts too much side force on the pump rod and wears the guide, eventually breaking it. My first jack identical to this was literally half buried in heavy grease laden dirt in a scrap yard in 1973. I bought it for the princely sum of $1.80. It was worn in every way, but being poor, ignorant, and with few tools I patched it and got the pump to work minimally. I used it to jack VW's and overhauled more than 200 engines ( and more) with this one. That put me through engineering with an MSME. In 1979 i was talking to a guy about it and upon seeing it he said he had one (much better shape) that did not work. $15 later there were two. 4-5 years ago, between the two, I built the one being used today.
It has no name plates and has a cast lift arm and saddle pivot. I think it is a WS as it appears much heavier than your pictures of the 1 1/4 o-boy. The scrap yard unit was well worn in '73, so it had to see years of hard service and suspect it may be late 50's vintage. I was so bad the saddle pivot had dragged the concrete so much that it wore off the material allowing the shaft to fall off the link arm and dropped a car. My arm was luckily out of harms way and i was only bruised from the 6 inch fall. Jack stands became standard following 1975.
I will add a picture later with some dimensions to help identify. I am quite curious to see when it might have been manfactured.
I still have three repair kits for this unit circa 1980. Maybe i will get ambitious and restore the one with the worst parts, now that i am retired.
Thanks again,
Bill