One more somewhat "hidden" variable to trip up the non-expert! If Bustas' daughter's frame had been the one on "ima's gift" ,it could have fooled even more people. I wonder what the cost differential is ,to produce all SB-2s or to have multiple frame types with all of their different materials, methods of manufacture, heat treating, handling/stocking, space allocation and parts identification, both for manufacturing and part replacement,along with the increased threat of liability?