Re: CE certification
I suggested Rouse as they are local to you and relatively inexpensive for vinyl, which is what they do a lot of. I wrongly assumed the boat was near to Cheltenham from your profile, but I now see it's on the South coast. Rouse had never used sunbrella when I visited them for a quote last year and I suspect the high price was to cover purchase of a quantity of material that they may have had no further use for, plus a bit of experimenting with stretching allowances etc during manufacture.
I ended up getting my new cover made by Mark Llewellyn of Neyland, Pembrokeshire (01646 600112) who did a superb job from scratch, including all template work. I had already fitted a fixed stainless arch to the boat as I had got fed up with wrestling with the old canopy sticks every time I wanted to put the old cover on or take it off, so there was no existing design which he could copy. Mark was very helpful with advice before I gave him the go ahead, his price was competitive, and the boat was in Pembs at the time, so it was a no-brainer really. He suggested a few minor changes to my design proposals, and the finished result is superb.
Frank Rouse would be OK for a cheap vinyl tonneau cover, but if you want a full canopy in sunbrella, a marine specialist would probably be better. Not sure if you're planning to keep it on a trailer; if so, you will probaby need a tonneau at some stage anyway.
Nothing is foolproof because the ingenuity of fools is limitless.