Ah Twisterowner! That is the problem. I went back to Dickies and asked them about the valves. The chandlery manager unscrewed the plug from a brand new Plastimo fender, only to find that it didn't have a valve either. Thinking it was a dud batch he fetched an old fender from the yard and tried that one as well. No valve.
So, it seems with Plastimo fenders, once you have unscrewed the plug you are, well, screwed.
I have tride pumping it up, but as soon as I withdraw the pump I have lost all the pressure before I can screw in the plug.
I have asked Plastimo about this - three times - by e-mail.
Dont waste your time emailing DVLA, they are dreadfully over burdened, ring them. After they eventually answer, I have always had my queries dealt with fully on the phone
Red Funnel Ferries - complained about a potential safety problem a few weeks ago, got a personalised email back saying someone from customer services would write back, nothing ever happened. Might forward it to the MCA to see what happens...