Mark,
Big Congrats on getting it figured out for sure and you didn't need to try and chase those 853M style bearings anymore!
I will blame my "old and unreliable eyes" for missing that little tang in your earlier picture. Also may have had something to do with the fact I was so busy trying to follow the thought trail of the casting number, that I overlooked the obvious.
Best of luck on the hunt for the 960M bearings. Would be glad to offer help if you have trouble trying to locate those.
Dan
