Well, all that's left is paint touch ups, add a shock cord and 'chute, and hit it with a dull coat to protect the cardstock. The nozzle should be darker than shown below and I have already repainted it.I updated the model RockSim model with accurate dimensions, actual mass and CG values, and the nozzle. It still has a phantom cone to simulate base drag. Final flight specs include, with a C11-3 loaded:Margin of 1.16 (note this used the 'phantom cone' tweak to account for base drag).Stable off a 42" rod.87' altitude.Optimal delay of 1.42s.If I move up to a D12-3:Margin of 1.1.Stable at 37".150' altitudeOptimal delay of 1.25s.I don't have confidence in the RockSim results (not that I really expected to). Most obviously from these sim results, it doesn't seem like the optimum delay should be lower on a D12 than on a C11. Next, I'm not sure how the large nozzle will affect base drag. To further confuse matters, I also found that, if I remove the 'phantom cone', the margin with a D12 is still 0.82. After thinking about said funkiness, Psuccess is about 25%.