Thanks Patrick, that's near enough. I'm trying to find out why RR Merlin V12 engines on MK VI Mosquito aircraft only have 10 exhaust stubs per engine instead of 12. My apologies for sending this personal reply to the list, but for some reason my email to the UK always bounces back undelivered. Anybody know why? George Bailey Objects Conservator Australian War Memorial Treloar Centre for Conservation 4 Callan St, Mitchell, A.C.T. 2911 Australia Phone: +61 6 241 6122 fax: +61 6 241 7998 email: [log in to unmask]