Simply put, since I learned the Dingle version from Derek back in the 1980s, I can say that his was virtually identical to a Larry Jennings version (of which there are many) and not Bruces. (This is just one of the things Bruce and I would argue about over the years.) Bruceswhich I prefer by the wayuses (ostensibly) four cards, not five. While Derek recalls (and credits) seeing Cervon and the Professor do the trick, what Derek had to see was the Professor doing LJ's 5-card version. Otherwise, logic dictates that Derek would have reinvented Bruces 4-card version (a version, by the way, Larry had as well).
In Fulves description in Epilogue (where two versions are explained, not just one), he notes that the trick appears to be in general circulation in the US and Europe, but the clear implication is that LJ invented it. Mike Maxwell, in The Classic Magic of Larry Jennings credits the underground for naming the trick (the version in that book is slightly different, and this is where the 4-card version also appears).
But the bottom line of all this is thatas noted earlier in this threadBill Miesel deserves the lions share of the credit. Hes the first guy to have published a small packet Ambitious sequence (Ambitious Ten in the June 1957 Ibidem). Furthermore, Miesel credits P. Howard Lyons for giving him the idea via a trick of his published in the March issue of that year called Three Up. This was a sequential ambitious effect using an Ace, Deuce, and Three with the deck proper.
I never felt Bruces claim had any merit. Im curious if anything about such a trick appears in any of his notebooks recently published. Because I would think, given his proclivity for writing everything down, that if Bruce was working on it, and LJs name didnt appear on it, it would be in one of those books. Can anyone who has them say?