Will do, of course, Richard, and thanks for the comment. I have one in at least GVF, previously shown on this forum, but was surprised to see this one from a dealer who specializes in bronze. I had to look at an 1875 narrow date as well to confirm my thoughts, but was safe in the knowledge that it was an improvement on my 'normal' F72 anyway, so not a massive risk. A good loupe is needed with this variety.
Give me a day or two, must add my F21 to your list, will check for others.
Jerry