Why? Genuinely curious as I draft the letters for Black Boar and often note "one of"...one, five, however many. Working on the premise that there is value in unique art and therefore, the rarer the more valuable. I would hope as long as it's coupled with "replacement" value it's acceptable? I'd hate to be doing anyone a disservice.I seem to also recall that you don't want to use wording like: one of a kind.
Custom or hand made is OK.
Lou Figueroa