AFAIK match pistols with short were used in Olympic Rapid Fire match up to... was it the 2004 Olympics? After that the match was shot with .22LR. AIUI too many shooters were starting to get perfect 600/600 scores in the matches - so they went to "standard pistol" configuration. Rapid Fire pistols with shorts were often ported, had shorter barrels, roll-over triggers with no pull limit, wrap-around grips - people would use four lower-velocity rounds on top of the last high-velocity short so they'd be less likely to get a late-shot "miss" on the last target in the 4-second stage. Now, the Standard Pistol is - unported barrel, .22LR, 1000g trigger, and no wrap around. So now there's recoil and trigger-pull to deal with, and scores dropped. (5 shots into 5 targets in under 4 seconds with the starting position for the arm below 45 deg below horizontal, it's a bit tricky taming the gun between targets).
Not that anyone asked.
I've been able to find non-competition grade shorts at CT, Al Simmons (Hamilton), and a few other places. But I didn't find it all that cheap. Back when 12-year-old me was wandering around Manitoba farms shooting gophers, a box of shorts in the pocket went a long way...