looking at pictures of my spreaders i can see that on 26/1/16 they were straight. then on the 12/2/16 one was pushed upwards. I remember between these dates sailing down wind, full canvass downwind in alot of breeze. Cant remember, but i think at one point a batten was caught in the spreaders.
a few months back i noticed the moved spreader and at about the same time i also noticed a slight list to one side.
It all makes sense now. the stbd spreader is moved slightly upwards and by the looks of things this has moved the mast slightly to port. this would explain the list.
Dunno what im tryna achieve writing this post...im hoping to just pull the spreader back down and for all to be sweeet....

Steve, you know the old trick of hoisting a pendulum bob up on a halyard? This will tell you if things are out of alignment. However, it cannot distinguish between a vessel list and a mast lean. Spirit level across the deck gives a rough idea of vessel list. Rough, because manufacturing tolerences could mean that deck and water level are not the same.
Builder's hardware stores sell the pendulum bobs.

When all else fails, take a photo, and use a ruler to check.