Hello Gordon,
I am using a Ro-Jett .51 SE. I made the wing panels equal, lengthened the fuselage 1/2" for engine and designed both wing and nose gear to be removable, so all of this added a tad of weight. This model as you know, has a rather hefty fuselage anyway. During my early planning, I talked with several about it, including Jim Young, Tom Niebuhr and Tom Dixon and they were all a great help. Tom Dixon strongly suggested at least a .46. I had a PA .40 SE and a Ro-Jett 51. They both weighed the same, so I went with the 51. It fits very nice. Total weight is now about 49 oz. I was shooting for under that, but this is what it is. I still have some clear coats, the boarding black walk strip, and the Bellanca logo.
Sure would like to see pictures of your build!
Jim