Hi Steve,
Yes, the Engels kits come with a 1:1 plan plus instruction booklet(s).
Putting it together is fairly straight forward, however:
The kit comes with the upper & lower hulls taped together, once they are apart, getting them backtogether is a bit of a fiddle.
The diving chambers are a real tight fit in the hull.
With the big lump of ballast in the hull, it becomes really heavy and that has to be in before the diving chambers and electrics are installed.
You can always e-mail me on
KenP