Assurance is very similar to the Envoy which Im just finishing off (my thread is in Working Vessels R&D). I believe several parts are used in both?
I found drilling out the prop tube exit to be very difficult. The MSW notes say to drill out with a large drill! I decided to start small and step up in sizes. I used about 8 different drill sizes but the last one still cracked the hull as the moulding is very narrow where the prop tube exits. You cant use a dremel either as the hole has to be drilled quite deep into the hull cavity. I'd probably suggest opening the prop tube exit with a couple of drill then use a rat tail file. Even so, I'd be very careful you dont crack the hull in that area.
My hull was a little narrow or, the printed rear deck card too wide. The instructions say dont cut down the deck card but I couldnt force the hull wide enough apart to get the uncut deck in. MSW say to build the rear deck and this forces the hull out. I couldnt get mine to go in and had visions of damaging the gunwhales \ bulwarks if I forced it too much so, decided to trim the rear deck a little to fit.
The hull is made from coarse fg mat so the bulwarks need a lot of sanding and filling with body filler.
The Envoy superstructure is an fg moulding whereas Assurance uses plasticard.
The rigging (which Im just doing) is a real nightmare. Envoy has no instructions for the rigging for the ships boats so Im not happy with my effort. Rigging for the masts is shown on the plan but now I've come to do it, found out there are no tie off points for some items such as the ensign, mast derrick and stern mast light. Never mind, I have managed to tie these off on the mast itself and they dont look too bad.
The rudder pintle is a right pain to fit so there is no binding but with a lot of care, attention and time, you can get it sorted.
All in all, Envoy is a good kit and seeing as assurance uses many of the same parts, should also make a nice project.