@lpar @bitterdonald @gooba42 @mttaggart @mwl
Note that whilst Scotland and Wales aren't legally independent political entries, there's nothing stopping you using https://dot.scot/ or https://eincartrefarlein.cymru/ (the latter is run by the UK domain registrar)
For any part of Ireland there's https://www.weare.ie/. Nic.ie is unfortunately a transport company. Oh dear Ireland.
Crown dependency registrars are https://www.channelisles.net/ and https://www.nic.im/home.mth