The best way to order EUR1's from HMRC is via the web chat facility which can be found here:
https://www.gov.uk/government/organisations/hm-revenue-customs/contact/customs-international-trade-and-excise-enquiries
From here you should click the Ask HMRC Online link as below:
The web chat staff have been told that Chambers can order the printed documents via this service.
If you have any difficulties ordering please email me at p.wrighting@britishchambers.org.uk