It's a Walker, it could either be a 757/767, the frame appears to be smaller than the 867, but the seal kits generally cover all series. It does appear that someone has added either a newer reservoir or drilled and tapped a vent, the original fill/vent is the Hex on the block.
Should, unless someone has updated the tank nut to a newer version, or updated the Ram. Oem would utilize packing on the tank nut and a leather piston seal on the Ram, versus a quad ring and poly ucup. It's always best to verify internal condition prior to buying a kit, especially on a Jack this old.