Hello Wayne, if you look at the mast and rigging there are also the spreaders on the mast. The wire coming from the mast head down through the spreader must be in a straight line, looking from the side, The other two sets of rigging wires are about 1 1/2 inches each side. That is for the main mast.
The mizzen mast spreader wire comes straight down, the gap apart for the other two is 1 1/4 inches either side at the deck. The location of these mast support wires is alongside the stanchions, make sure there is sufficient wood underneath to secure the eyes in the deck. You can use small screw eyes srewed down onto a small washer that looks good. You can first gently open the screw eye and slide one end of the turn buckles into them and then squeeze it shut again or have a hard wire extension connecting the two.
It is quite a game rigging with turn buckles and make sure they all turn in the same direction i.e. do not put them in upside down. The problem with the design is that the main cabin covers all access to the controls and when the mizzen mast is mounted it is locked in place, so you can't change batteries without taking the mast out.
So go with all day batteries especially if you fit a propellor, I could not see whether there was a prop shaft present. Do you have a rudder? Mine measures 2 1/2 inches at the top and 3 inches at the bottom and fills the space allowed for it. It only just controls the boat and when tacking the motor sometimes needs to be switched on to get her around.
The motor is not much use but does bring her in so you do not miss lunch, you only need 10 watts of power as reversing it with the wind behind is a waste of time.I would run from one 6 pack NiMh pack and either use a voltage reducer for the receiver or fit an esc which will have an internal BEC. You will need 3 ch min.
I would use a coarse bladed prop which has less water resistance when sailing.
A standard sail winch works fine, on another thread the guys who run Ingas regularly swear by arm winches which are a lot easier to install.
The deck needs a ply sub deck and then some planking. If you do this then the planking should run parallel to the outside curve of the deck and be joggled into a double width King Plank down the centre. Straight line planking is for commercial decks, yachting decks are curved. The planking need only be a sxteenth of an inch thick but use sawn wood not knife cut wood which usually has a ragged edge.
Bye for now,
Roy