I'm been to two local retail/commercial store specializing in hydraulic equipment and repairs. They both were unable to assist as I did not know the make and model. One tried quite hard but were unable to locate compatible seals in their stock. The other just blew me off.
I only need the "U"...
I have exactly the same jack ( an unknown H50). Todate I have not been able to identify the make in order to buy a seal kit for it's plunger. Have you had any luck Hope to hear back from you.
:)