Does anyone have a picture of the stock oil pan? A picture of the outside (bottom) as well as the inside (top)?

 

If you look in the Haynes Manual you will find a pic of the outside of it, looking up from under the pan. Not sure about the inside of it though. You might even just try your local Mazda shop and see if they have one laying around that you could look at. Either that or a boneyard, but the yards around here dont usually have engines parted out and sitting around.

 

I don't seem to have an external pic but here's an internal shot from when my engine was rebuilt last year.