Well, if you put the bolts back in the pan and moved on, I don't think it would be any worse. The issue is usually that the gaskets harden and crack from heat and age and so everything might seem tight but you have seepage from an area where a piece of gasket fell out. Personally, if I was in your situation, and using it for a driver (ie, no down time), I would liberally douse the lower engine bay / block with Simple Green or another degreaser, and scrub as much as you can with long handled brushes. There is not a ton of room to work but you can get at it if you try. Beware, it's usually a dirty job.
The other thing you could do is take it to a detail shop with a steam cleaner and have them steam clean the engine bay and underside. The only problem with that is steam = moisture and these things are 20 years old or more and may not react that well to it (electrical, etc).
I think it would be best to determine where the leak is coming from before doing any major work! Also, cleaning to me is essential because dirty parts aren't happy parts when you are assembling things, and who really wants chunks of grease and road kill falling in their face??
Welcome Visitor! Please take a few seconds and 
