Jim said:
However as Iain has pointed out, note that the anodising produces an
*insulating* layer on the surface. So mask off any areas which you need
to ensure remain conducting for ground contacts, etc - or be prepared
to
abrade them clean of anodising afterwards.

Hello Jim. Thanks for your views here. For a finished product it does
point to anodised. I wasn't aware it wasn't conductive, so that's worth
knowing. I'm assuming that I should cut out main holes before
anodisation - holes for tube sockets and XLRs for instance. But then I
should drill holes holding the top plate to the chassis after
anodisation so the screws make contact with the aluminium. This sounds
logical doesn't it?