RE: Molding a Dirty Bridy 60 Fuselage
You can also take a 3/8" or 1/2" drill bit and just start a hole in your parting board, you want a "V" shaped dimple, this will serve as to match up the two mold halves. I would not worry too much about the parting board, just wax it and use partall (PVA) and it will release.
The rudder being on the parting boards not a problem, I'd just scratch in where the rudder starts, then use that as a reference mark for trimming the fin.
The wing saddle area isn't a problem either, just put a piece in to fill the area, I'd make it an inch or a inch and a half thick, you don't want to have that closed in on the mold anyway.
If your parting board fits the fuse well, I would just get a 3/4" MDF board and cut a rough outline of the fuse out of it, then attach what you have to it. I'd also get some 1x3 pine and make the shadow box out if it and the MDF.