I understand that it is legally true BUT
in practice not many UK schools will rent you a hele without a lot of caveats, probably including further training/check-outs/continuation training/area famil/maybe even requring study of UK Air Law Blah, Blah. ( Why - well if you have just a bare US PPL(H) in order to keep you and the aircraft safe and to avoid complaints from ATC etc.)
If you are talking about buying your own, then why not set up a US trust and use N-Reg?