You have the cleanest bandsaw I have ever seen. You sure you actually cut anything on it?
The plaster is poured in over the rubber mold. Some parts are glued together, some are held with screws so they can be opened. This requires a nut or threaded brass be glued into one half so the other half can be screwed to it....When you made the mold with that plaster, how does it account for the rubber mold when you place it into the plaster before you do your resin?
Does the plaster shrink enough to allow the rubber to sit properly?
Also, How are you putting the two sides together when done? Are they just glued?...
If/when I make resin casts yes. But for now I'm making fiberglass parts, only one mold half is needed....Have you given any thought to making an RTV plug for the inside of the P1. You may have better control over the final wall thickness...