tin house basescoat

I'm trying a demi-metalic for the tin roof..used 3 drops of gun metal grey, 2 drops of rainy grey and 1 drop of soft blue.
will see how it turns out when shaded and highlighted.The ridges look like they might be wood and not folded tin so doing them brown as well..

I've found the walls take about 3 coats for good coverage over the primer(got one done just letting it dry) and doing the wash for the walls and floors and drybrushing the highlights backup on the walls before painting the windows and doors works better.

Heres progress so far..roof might have come out a bit more cast iron color then tin(might need lighter grey)