Today is 9 months and 4 days since receiving the GRP hull. The number of hours spent has not been logged and as the level of detail is up to each builder I reckon it's impossible to quantify.
I think I will have this finished within the 12 months brackets despite having another build starting soon.
Really time isn't important as long as it's something you have and enjoy spending it
EDIT
I have abandoned the magnet idea for the wheel house roof. I can secure it with two screws and clamping plates through the windows over the doors. I'm sure it will be unobtrusive and a bonus of not fitting glazing