I was just bitchin about non metric stuff in general.
As I said , this was just mild curiosity about N reg planes in UK. I take it there's no reg that requires you to rip out the altimeter and replace it with a suitable one.
I guess I was just wondering as missetting the altimeter can do all kinds of wrong things. I misset mine once ( out by a whole inch). Of course I picked it up on my preflight instrument checks where the altimeter was definitely not showing field elevation ! A quick flick back to the ATIS set me straight.