If you're lucky, your leak was coming from the upper sparkplug seals, the ones you put into the valve cover. If so, then it'll quit leaking. If you put those in, & it quits leaking, I'd declare victory & quit worrying. Nobody can say over the net which ones were actually leaking.

If it keeps leaking, then you gotta do those lower seals. Your valve-cover gasket should still be ok to take off & put back on. Those things get hard & brittle with age & heat, but that doesn't happen very quickly. Got a repair manual for a good procedure for R&R camshaft & caps??