Toyota Repair: Oil Seapage, 4runner sr5, seap

Question
I would appreciate some advice for an ongoing miner oil leak. I had this 1995 4runner sr5 v6 3vz since it was new and has been in the shop where they said they witnessed an oil leak from both valve covers and the left cam plug all which were replaced. I got it back and the leak now appears to be a seap of two drops collecting on the bell housing but not dripping. Is there something else not visable or somewhere else i could check for a leak?  

Answer
It may be the rear engine main seal that is leaking, this is a big operation that requires transmission removal, to be sure where the leak is coming from I would suggest that you have the repair shop add a flourescent dye to the engine oil and drive it for about 300 miles, the oil leak can be pinpointed by checking with an UV light, if the shop you are dealing with now can't do this find someone who can, it may just save you some money to find out where the leak is coming from instead of having someone guess.