John Cornelius demonstrated a fine coin pass in his lecture. Not sure if it got into that magazine. It's nice to get a "burn" or optical effect in a coin transfer.

Digression: The John Cornelius Slow Motion coin vanish starts on page 736 of The Pallbearer's Review, May MCMLXXIV (1974) The followup item from Freeman and Dingle starts of page 760. Though Slow Motion type routines are not about getting an optical effect on a coin pass so much as seeming to fold away a solid metal coin.

I think dramatic tension too. I know the first time I saw Vernon slow mo vanish a card the feeling was "oh it must be... oh wait, wow!"

Not sure where Cornelius published his retention pass if it isn't the SMCV in 1974. Same for Freeman. I had the Zarrow vanish on the Encyclopedia of Coin Sleights DVD set. All apparently are the same.

The Slow Motion Coin Vanish goes back at least as far as Vernon's Tribute to Nate Leipzig.
The film Spirit of Magic shows Vernon doing his interpretation using a card. Harvey Rosenthal continued that line of thinking back into coin tricks.
Geoff Latta played as if he had lapped the coin so the surprise comes when the coin appears at this fingertips.

As mentioned earlier, a coin transfer sleight that gets a "burn" is described in Downs book, then again in Art of Magic, twice in Bobo's (once for parlor and again for closeup)...

Should I go looking in those first years of Sphinx?

The Zarrow vanish used the thumb base to minimize finger movement. Freeman apparently did the same, as did Cornelius. Zarrow showed me his vanish in the 80's, but I can't find any published reference to any of these three, which seem to all be the same. Independent creation? Did no one publish the idea? I have the Zarrow vanish on the Encyclopedia of Coin Sleights set, is that the only reference?