Ha, I forgot about the washers - yep, they were also a bugger and whilst some are fitted, the others got lost in the long grass.
Re the temp, I'm also having the same trouble brining it up to temp - I did get to 325 on my third burn and then closed off the bottom vent (not entirely, it was a a quarter open) and closed off the chimney,. Leaving the vents fully open - cam back ten mins later and the temp had dropped to about 200?
I had plenty of fuel in, it worked fine all vents open but blasted through the fuel.
Thankfully I'm doing the bavette direct today so not so much about the temp control but really do need to nail this control down for the slower cooks.
(piccy is of the marinated skirt).