Hi Mike,
I have just put a few parts into Matsar Coatings and have heard they are good from a VMCC friend, however, they work from an anonymous looking building, not even a sign out side! They were formerly known as Northumbria Specialist Coatings and are based in Cramlington. I am having some stuff powder coated and some stuff wet painted, I will let you know if they have done a good job. I am expecting that back early this coming week. I don't know about tanks but my friend has have them paint some frames etc. He is very particular and seems happy. Good value too.