As the white gloss is a bit thick and also because it isn't total bright white, I decided to leave it for the time being at least.
Having tried a few different ways, I finally have some shutters I like. The doorknocker was missing too, so I took a mould off No. 47's knocker & cast one in resin. After a bit of gilding, painting & tweaking I'm pretty happy with it. I reckon the house looks more cheerful now!