SIR,
Have you tried the likes of Silvermans, Ace Cafe or Grand Prix Legends, they are all UK firms, and sell very good wool turtle necks or as know here as Polo necks or Roll Necks, they are sold as RAF- Air Force/Submariner Sweaters, usually off white or navy blue, I have several and they are great. There is also a firm in cornwell call sou'west chunkies who will knit you turtle necks. Look at threads on this website, Woolly Pullies, fishermans sweaters and RAF- Air Force/Submariner sweaters. Good luck, hope you find something suitable. Rgds Steve.
That's perfect! Thanks!