SkF green 38mm seals are the best for those Marzocchi's. https://www.universalcycles.com/shopping/product_details.php?id=70237
Damper side probably has a OTT feature similar to DVO, that can add pressure if installed incorrectly. And damper side can get a little pressurized from old oil aging.
Total teardown should get things working close, but I wouldn't sweat it too much right now.
Stock oil is Golden Spectro 125/150. I tried using a different 7.5w motorex maybe and it was too thick, rebound was always too slow. So it's a good idea to buy a quart of the golden Spectro rather than risking a poorly riding fork.