Good morning, they are injected plastic injection molding. Not resin or 3-D printed. They are brand new moltds which we made mine, All of the modern boats come with the T 55 turbine engine. If you want the turbo charged Alison kit. You would want to buy the Griggs Ace Hardware 3 boat, and if it’s not available, you want the hydroplane museum multi kit. As it has both engines in it and 4 sets of decals to build any of the boats. The decals are also waterslide. Thanks, dave