just a quick and very brief update, rivets for those that require them are obtainable at
www.sapphireproducts.co.uk
3/8th dome head 1 1/4 long (if using 5mm angle iron and 10mm armour) bag of 100 costs £32.00 + vat
and if using 8mm side armour use 1" 3/8th dome head @ £18 per 100. +vat they do have counter sunk variants amongst many others.
cheers
Richie