If you take a bit too much off one of the torpedo blanks, it's easy to add a coat of filler and sand again...
...and the fins are easy to cut from thin brass or tinplate. Superglue them into their slots. Notice the bits of brass with a bolt through them in the background - these will be the propellers.
A close shot of 8 brass squares bolted together and cut down to a propeller-shape using a mini-tool grinder. Easier than using a needle file.
I spun them in a drill first against a grindstone to get a perfect circle...
A bit of solder and there you have a set of torpedos. Bend the props into a curved counter-rotating position and remove the rest of the copper rod.
The propeller unit uses two props and a small spacer cut from brass tube.
Here you see how the bung is made.
Drill a circular hole over the rudder to give access to the tiller attachment. Sand down a circular bung until it is a snug fit, then glue to the bottom of the hatch. Remember to seal both items well once they are made...
Here I cut thin slots with a mini circular saw Dremel attachment - a knife would be fine...
The mast is straightforward. Cut out and glue the main mast and cross-piece. The cross-piece has a slot cut in each half to make a clean joint.
Once the two items are dry, sand the ends of the cross piece to fit inside the main mast and glue it in. Glue the little pin hinges into the bottom of the mast legs, pointing outwards. The springiness of the legs will let you squeeze them together and fit the pins into the holes in the brass mount.
Glue the mast mount, and the mast strut mount, into slots in the cabin roof as shown here. A sanded-down radar dome goes on top to complete the mast, and the bent piano-wire strut goes through its brass mount, and into two holes drilled in the mast legs about half-way up...
The smoke cylinder and the circular plugs for the rear hatch are made by sanding balsa on a spinning drill similarly.
The plan shows the rear hatch and smoke generator on a single 'T' shaped base - I decided that it was not needed because it was easy enough to remove the hatch-bung on its own...
