Could it be the front main seal? Was it on the pulley/belt? If so, it could be front main seal getting on the pulley and flinging up, as that does happen.

We thought of that, but it didn't look like it. The seal looked fine when we pulled the motor. We replaced it anyways. 2/2 for front main seal install failures doesn't seem likely.

The thing which is hard to see in the photos, is that it is not simply splattering onto the top of the oil pump. It's as though it's originating from a seam. But there was nothing trickling down from the valve cover or cam seal.

I organized a tow to take it to a shop tomorrow. I trust that they will be able to sort it; at least they have a lift and facility to do this in less time.

So....back from the dead...

It's still leaking after re-replacing the oil pump but there is a new question... is there an oil galley plug behind the water pump at the front of the block? If this were leaking some how, then it would kindof fit with the location it would be dripping down from with oil settling on top of the oil pump (having dripped from behind the water pump), but not visible from the cam seals....all on the passenger side.

Does anyone have an image of a block without the water pump? I try to google image search and it's just showing engine bay shots

https://www.miataturbo.net/attachmen...ine=1405024038

With a higher pressure oil pump, could a leak be exploited by that gold oil plug? I didn't touch it, but I don't know if this was done by the previous owner of the block. This would also make it appear like it's leaking from the high pressure port of the pump

Sorry to hear that man. Do you want to come look at that spare block in my garage?