I think you may need to get a Euro CoC from the supplying dealer in Holland?
Might be worth going back to them and seeing if they can supply you with one...
The alternative is to contact the UK's Vehicle Certification Agency (VCA), who issue a certificate under their 'Mutual Recognition scheme'.
The other alternative is to go for SVA - Single Vehicle Approval - which is like a very thorough MOT and will check that it conforms to the requirements. This may be the easier route anyway as you'll need to get it MOTed to tax it once imported anyway.
You will need to make sure that the bike has MPH markings on the speedo - either on the dial or it can be a decal overlay. Also, you can pass an MOT using just beam deflectors, despite what some people think! http://www.motuk.com/bike/1-6.asp
See section "Masks and Converter Kits"