Hi, yup, those lugs, specifically head tube are identical.
The seat tube is 26.2mm which means it may be a vitus 888 tubeset. Further digging and emailing has revealed it may well be a Bertin C56. This picture of a C56 (early 80's apparently) is the closest match I have yet seen to my seat cluster...
I have emailed Geoffrey butler regards the EO on the bottom bracket, hopefully I will get a reply. Might be just as easy to call them on Monday!