Mine is not a 5 hole gearcase. Photos are in email to you Scott. If you would like to share you may. The new case comes with a bearing pressed into the pinion area and another under the water pump plate area. One is shipped with the case also. Not sure where it goes. I had not thought of it being a 6hp case. That should make one heavy duty gearcase for that small motor. The wings are on the tip and look easy to remove. This case also has the holes in the A/V plate for the anode. I talked with BRP and they tried to chase the number, but info has been deleted as to what that number was used on.
Here are Dan's pics of his housing. Looks like the one posted in the first entry... The determining factor of what, exactly, it fits would be by the diameter of the pinion gear support bushing as the 6hp and 9.5/10 hp used different diameter shafts.