Almost 25 years ago at a shooting match at Western (name of the nearest town) I shot a re-entry match set up to duplicate the Hickok-Tutt shootout. The match directors took a knock-down target (a "Pepper Popper) and fastened a standard IPSC cardboard silhouette to it. You had 3 seconds to draw and fire one shot; a hit had to hit and knock down the knock-down (not just hit the cardboard silhouette) to count.
Did I mention the range was 75 yards?
When you missed the target, you could sign up for another $5 and go to the back of the line to try again. . . this one match actually covered most of the costs of the shoot that year, because it was rather addictive (plus the side bets were insane).
Something similar could be done for single-shot pistols. Maybe go with a similar knock down concealed behind a silhouette (deer, buffalo, man, Darth Vader, whatever) at 50 yards, with a slightly-longer time limit.
Useta-was, under-the-table derringer matches were popular. These were a blast, but have largely been discontinued for safety reasons, both real and imagined.