This post just explains a simple way to layout and building jig for one of these helm stations.

I just use saw horses and some particle board or plywood.

the ply is made into one plane by overlapping and marking for miters or butt joints.

once cut to fit they're made into a relatively flat surface by cheek blocking underneath and the whole set up can be screwed to the saw horses so it won't shift around too much.

next the outline of the base is drawn on the flat working table. If your cabin will have to bolt/screw/fasten to a wood or glass deck then you'd be making a lower flange plate of the size and arrangement of the outline shown here. This version is drawn where the cabin base will be built so it can be welded to an aluminum deck.

this image shows a group of 'pizza pan panels' already tacked on to the plywood base or working table to explain why the base layout is done at the table ht.

the last image shows how to 'weld to plywood'. By using small tabs of aluminum (1/8" x 2" x 2") with a few holes in them you can screw the tabs down where you want to tack. Then hold the cabin base panels together with vise grip type pliers on their inner edges and locate them to the base pattern and tack.
If you were building for a bolt-in structure then a 2" -3" wide flange would be screwed to the ply, and the panels would be fit to tack every few inches continuously along the intersection between the vertical panels and the base. Since it may be difficult to get a drill motor extremely close to the vertical pans and still make a nice vertical drilled hole- it may be the best time to layout and drill the final holes to size?
This same method allows wood to be used to make formers for the metal, seriously reducing jig cost and saving metal. since most formers only need to be in place until cold formed panels or sheet goods can be marked taken off and cut then returned to be held in shape while tacked.
cheers,