The Victory, if I remember correctly, had a relatively short nose and the choice of two tail moment lengths. Depending in how long you build the tail and how light it's construction is, and factoring in that you are not going to use the heavier .60 size ignition engine and components that they require, you may be needing some nose weight, in which case you may want to consider making your engine mounting plate from a piece of 1/8" thick steel. You can build the model, and get through most of the finishing stages and then mock up the engine mount and see where you are for balance at that point. If needing nose weight, go with steel. Get it all drilled and taped, clean thoroughly, and then a good paint job. If weight isn't needed or desired, then go with the aluminum. The sheets that K&S sells in several thicknesses should do the job and is pretty hard but will still allow drilling and taping. In my work, when repairing an aluminum machine part that I was concerned about a tapped hole holding up, I would make and install a steel threaded insert out of a proper size steel screw, thread the plate for that and JB-Weld that in place. If you don't have access to a lathe, that can still be done with a steady hand and some care. Another possibility is making the mount out of 1/4" aircraft plywood. You might have to adjust the beam locations to get the engine center line correct. Goldberg Models ( I think ) used this method to mount engines in R/C trainers with the thought that in a crash, the plywood would break out and save the engine and the rest of the nose. I don't know how successful this was in the end but is worth consideration. The size of the mount that you would need isn't that big and what ever material you choose, it should be plenty stiff.
Type at you later,
Dan McEntee