Ford 9 inch axle seals

Hi All, need some information about how the gear lube is retained in a 9 inch.

My 81 had a seal on the outside, just under the retaining plate, that looked like this:

https://shop.broncograveyard.com/images/timkenset20.jpg

But I watched a YT video on replacing the bearings, and it didn't look like an outer seal was used. Just the bearing, then the retaining plate. When putting the axle in, he said something about a seal that was apparently already in the axle tube.

And when I google "ford 9 inch axle seals", most of what shows up looks like this:

https://static.summitracing.com/global/images/prod/xlarge/yga-30117_xl.jpg

Where does that type of seal go?

the seal must be between the retainer plate and bearing. if it were to be put in backwards it would have the bearing not getting oiled and it would be open to the outside. and the collar would not fit either

It's been a minute, but if I remember right, the second seal you posted goes in the housing itself, used on early 9" rears.   Pretty sure my 70 Torino uses that type (and ball bearing axle bearing), where the first one you posted (looks like a Timken Set 20?) is a tapered bearing, and used in later 9" rears.  

Yes, the first pic is a Timken Set 20 seal.

So if the smaller, earlier seal goes in the axle housing, what lubricates the bearing, which I assume is outside of the seal? Is it a sealed, greased unit or something?

Sealed ball bearing, I'm pretty sure.