Hi,

The red block can have three places to leak out besides the front and rear oil seals for shafts.
From where you are spotting the puddle and from the way the engine is slanted,
One of them can start at the back of the head up under the valve cover.
It has a poor seal mechanism in there.
The seal thing is a cheap metal disc coated in a thin rubber coating that I think is barely sufficient to seal when new.
As time takes it’s toll the diameter shrinks up about .010 in diameter. That’s all it got when new so it ends up with nothing working in there. It just sits there blocking and not sealing.
The Flame trap system gets blamed for contributing to this but I seriously had a problem believing it’s all that.

I recently change one on my 1992 and have determined what has been going on. I had one of those seals in stock, to put in and measured things out.
I went ahead and used my poor investment but I’m considering making up some an aluminum disks for my four cars in that diameter and putting an O ring groove in them. This way I can get about a ten to fifteen percent compression ratio on the rings diameter that I decide to use. It will not creep or seep anymore from the holder area it’s in.

I know this doesn’t help you much but the rear seal is still available. It will still work for a short time as it’s leaks so slowly it goes unnoticed way back there.

The other place is more forward, the oil filter itself.
It can be the oil pressure sender as it’s possible for the senders crimped top to leak. I had one of those but it’s a trail.
Rare is when the head gasket gets to weeping oil right above that, so I don’t count it much.
The water pump can collect upper cam seal deposits but yours is not there.

On my 1991, I just had to replace the gasket under a flat plate on the other side on the engine. It’s in the place where I think mechanical fuel pumps use to go.
First and only one engine to leak there so I was surprised it got me for so long. (:)
Due to the slant and slope rearward, the oil runs to the rear along the top on the oil pan lip. It then drips on the right side where you see your spot below the down pipes.

In all these scenarios, the size of the puddle, that you suggest, determines the probabilities but don’t dismiss the rear crankshaft seal.
If it’s leaking that will blow back under the whole car given enough time.
A static leak and or a dynamic one, will show their own two signs.
Being a skilled hunter starts with having some “Red” block heritage. (:-)

You just need to “read your signs.”
I think there a comedian that uses that line … but oil leaks are not funny. (:)

Phil