I got my gaiters (and all my Slade Wallis leatherwork) from Tom Stemson. They are excellent quality and he can make them faced (lined) or unfaced. At the time I paid £75 + postage for a lined pair. He was then charging £48 for the unfaced.
If I recall correctly I received them a week after he received my cheque so there's a pretty fast turnaround and I hadn't asked for a rush job.
His e-mail is Tommy.Stemson@btinternet.com