Managed to acquire an example of Warlord Games' Cruel Seas starter set sprues.
There are two sprues, and each makes two different boats: a mid and late S-Boat and a Type 1 and Type 2 Vesper MTB.
I made them up as intended, adding nothing with the sole exception of the Vospers' masts...which are way oversized.
If one wanted to add mast's to these vessels I would recommend nylon house brush 'hairs'. You could use fine wire but I have had bad experiences of putting my hands over models to move them without noticing a very sharp upward pointing wire! And they are a hazard to children.
The boats are great. ..highly recommended.
I am trying to blag an early review copy of the starter set for review .........