OK, Here we go. I just searched for GB SG# Y1750, the 19p Elliptical Machin issued in 1994 on
ebay. What came up was SG# Y1771 - the "new" SG number. The listing shows both numbers, the Y1771 being called "Ex 1750". I was able to find the stamp using the old number. Just a word of caution: Double check your order and make sure you are ordering what you want. Its very confusing. I also saw #Y1751 incorrectly identified as a 22p stamp on its listing. It should be a 20p stamp.
Jack Kelley