As good as it was there were always going to be limitations on painting quality when spraying the car in a backyard shed. I'd tried to convince myself it was
patina but in some lighting situations some areas looked a bit 'iffy'. I'd also clumsily taken a chip out of a rear guard and filling the crevice with droplets of paint would mean cutting back and smoothing off around that area, with the associated 'blending-in' concerns.
To cut the details of a long, nerve-racking, experience short I ended up going all over the car with 1000, then 2000 and finally 3000 grit wet-n-dry, pressing very lightly on any edges.
I'd research buffing and polishing techniques on the web and asked a few friends for advice but I came to the conclusion I'd pushed my luck about as far as I was game. I contacted a car-detailer and he came and finished it off.
Over the moon with the results.