I would say they only ever weep quite slowly, so I would think you'd be fine to put it together and drive it to a garage, to be honest. Especially if you've cleared the breathers. Nip up the cam cover bolts to their specified 8nm as well, just in case the leak has been precipitated by one of two of them working loose.
If it hadn't taken months for that oil to build up the plug wells would have overflowed all over the place and the problem would have been very obvious before stripping it down.
I'd agree with that, the oil doesn't gush out, so weeping seals shouldn't be a problem if you're only driving a few miles, especially as you've cleaned up the most of the mess anyway.
Contrary to popular belief, oil in the plug wells shouldn't cause any major problems to the engine running, it's just the mess it creates and when it gets really bad it will burn on the manifolds and start to smoke badly - don't ask me how I know! It's more embarrassing than anything else, but leave it long enough (and we're talking extremes here) there is the potential for the oil to combust. If it's not smoking yet, you should be good for a couple of hundred miles.
High tension electrical transformers use oil as a coolant, so it's very rare for it to cause firing problems on an Omega, but water in the plug wells (dripping from the scuttle) is a different matter all together, and that does cause firing problems and ultimately damage. Oil itself won't cause arcing problems.