FAA IR in G-reg c/w UK CAA PPL
For those considering the FAA, note that the UK CAA allows you to use your FAA IR on G-reg aircraft. You can use the ICAO IR outside the country because as long as you have a UK CAA/JAA issued pilot's license then you are flying under the rules of the license issuing country (UK). Of course you may only use the IR for private flying and thus you cannot use it for any hire and reward.
Source of info - CAA FCL. PM me with your email address and I'll send you a copy of the email from FCL that confirms this.