In the aluminum section of the pattern numbers for Wagner pieces in the BB of Smith and Wafford, there is a number 364 and there is a number 366, but there is no number 365. Which means that the author did not know what the number 365 went on at the time the book was written. But if you say it is not aluminum it does not fit. Unless somebody made a cast iron piece using the pattern that was used to make an aluminum piece. At any rate, it would be very coincedental if this piece does not fit as I am saying. So Dale it appears that you may have found a missing link here. :-/