I thought you may find this useful.
If I was you I would try the 378581 10 3/8 x 11 1/2 next
Or you could go down to a 12" pitch in a bronze prop which the number is SMC54 here is a nice example of that on ebay right now
http://www.ebay.com/itm/MICHIGAN-SMC-54 … Iz&vxp=mtr