To recap...I bought my 65 in July of 2007. It had 110,000 on it, 20,000 on a rebuilt Aamco three speed auto installed in 1990. The car obviously was driven some from 1990 to 2007, but not much.
Anyway, the tranny was fine when I got the car and remained fine for the two months or so I was driving it some. In October 2007 I put in the garage and started taking it apart, doing body work, etc. Within a short time the tranny started leaking. It go worse and worse. I figured it was old and seals were dried out. The car was not driven at all during this time.
Fast forward to last weekend...with the car mostly reassembled at last, I took it out for a drive to test the speedometer cable. Really just a couple of miles (at the most) in town.
The transmission has not leaked since.

 

that may not be a good sign, something could have rustles inside the tranmisson and lodge itself in the orifice fluid was leaking from.
i would take it to a shop for a flush and filter, then see if it still leaks, then do the seals.

 

Obviously the next step is to remove the current trans, dissect it in the name of science, and replace it with a 5 speed or something similar.

 

I think thats normal, but lucky the cork gaskets are meant to absorb and hopefully help stop the leak. but who knows, as long as it works!

 

Every car is different but here is my story. My 66 was given to me with 74,000 original miles. My Dad and his friend who he got it from obviously did not drive it much. It leaked from day one but I ignored it. When the tranny started slipping I took it to a local reputable shop and they adjusted the bands. Ran great for a few weeks and then all the seals just blew out. I think having the bands adjusted put more pressure on the old seals and they just gave way.

My suggestion (from a guy who doesn't know crap about trannies) would be to have it looked at if you are not a tranny guy.

 

My C4 became a leaker after I installed the fluid and dip stick. I used a "Chinese" chrome one. After the third and replacing O rings I installed a racing type with the top seal where you install the fluid. It has a "hat" type seal on the bottom. I still had a leak about the size of a quarter as I couldnt get it to stop where it entered the top of the pan. As the car sat in the body shop the fluid( I'm guessing) would flow back from the converter or someplace and start a leak. If the car is driven then the leak stops. I am putting the finishing touches together before I am finishing so eventually I will have to go back and solve the problem. It seems to have stopped lately but we will see when I stop starting the car to work on it and start really driving it.