Based on the pics, the pump area is just fine. Set the gears in the BH and see where they contact, you will see that nothing contacts or happens in the gouged inner area around the stator support. Clean it up to remove any high spots and call it a cay.

The 722.6 was used behind the M104 ( inline 6 ) and 4 cyl that is a cut down inline 6. look at 97 C280 , 97 E320 , 97 SL320 , 97-99 S320

As for swapping gear sets, Chrysler used 4 different ratios and MB 2. MB had deeper gears for 4 and 6 cyl and a taller set for 8 / 12 cyl. Mix and match will cause limp mode.

Something to think about, the trans made it this car with just a pump lug failure, had it not failed the trans would still be going. Clean it up, change soft parts, frictions, torque converter and other bits, then drive.

On the pump lug issue, most pumps gears are made of powdered metal, the material is somewhat brittle and I've seen lugs come off in other brands of trans before. and, never flip over a used inner gear, the reversal of drive forces can cause the lugs to break off down the road.