91 500sl transmission problem

[sbin]

Wife was driving the 1991 500sl with 70k miles when the car lost power and stopped.The engine was running fine but the car wouldn't move in any gear even stranger the car would roll when in park.

While removing everything need to pull the transmission I noticed the transmission mount on the back case had been broken.While taking a closer look noticed that the rear output flange would spin with the transmission in park but the output shaft would not

Turns out the rear output flange splines were completely stripped and the rear bearing seized!
The transmission appears to function normally otherwise
Dropped the pan and it was surprisingly clean as was the filter..

Found a rear transmission case with good bearing at pullapart junk yard for $10 but can not find a 4 tab output flange.All the 300 & 420 with 722.3 transmissions had 3 tab flanges.

Can anyone suggest a good place to get a used output flange?
Would like to avoid dealer price on that item.