I can't see the pictures here at work , but that front washer should not have a shoulder and if that measurement is right then you have a problem there , it's too thin. What is the thickness of the shouldered part?

I'm going to stick with my original assessment that the front input shaft and from drum assembly were not fully seated and the front drum wore away the front washer/spacer because it was forced against it.

No gasket sealer is needed on the front pump gasket or on the bolts ... the bolt holes are dry ... I have never had a leak with a plain paper gasket, the o ring around the pump and the correct pump bolt sealing washers.