you could contact model boats magazine, as they did an article on a full scratch build some years ago, they may be able to provide copies.
OR if you search a bit back on this section of the site, you will find my own Mersey build, which uses same hull and cabin as you have.
The upper cabin is a LOT of hard work to get the flying bridge right, so be prepared to do some test fitting with pieces of card first before cutting in to plastic sheet or ply.
One word of advise, same given to my by Models by design. "keep the build light in weight", or it won't move right in the water and you wont be able to get it to sit on correct waterline., that why I used plasticard for all the build work, to keep the weight down as far as possible, saving the weight for the brass hand rail fittings. as the white ,metal ones readily available snap a bit too easily for my liking and didn't use them.