Article 150 allows you to exercise the privileges of an FAA licence on a Annex 1 aircraft i.e a non EASA aircraft.
Deeming a non-United Kingdom flight crew licence and any Part-FCL licence valid for non-EASA aircraft registered in the United Kingdom and deeming a non-United Kingdom radiotelephony licence valid for any aircraft
150.—(1) Subject to paragraph (2), this article applies to any licence which authorises the holder to act as a member of the flight crew of an aircraft and is—
(a) granted under the law of a Contracting State other than the United Kingdom but which is not a Part-FCL licence;
To fly an EASA aircraft you will need to compete SRG 2140 and comply with the notes attached to that form.
N reg aircraft operating into the UK fall into a totally different category as they are not based in Europe.