I let a friend who was here from RSA cherry pick my .303 collection, then kept about 100 decnet ones for trade - mostly gone now after many years - and gave the rest as a donation to the IAA Auction. Since I didn’t go to the auction the next year and wasn’t at the show the following year, I never really found out how well IAA did on it. Well, I hope. There was penty of good stuff left. I had about 1500 .303s (no “dates” - that is, I did not collect different dates) when I broke it up.
I actually had two slightly different of those short blanks. Proportionately, they look the same as the Snider one, pretty much, or at least to my memory. In your photo including a .303, the size difference is startling, of course. Thanks for the clarification.