The length limits were put there specifically to screw over the minirevolvers (mainly NAA plus the old FAs). The five-shot limit was to screw Derringers.
NAA Minirevolvers and AmerDerringers were declared "junk" in several of the city and county ordinances that were ancestors to the eventual state-level "junk gun law". The all-stainless American Derringer two-shots were another high-quality type of arm banned for the *stated* reason that they're "junk", but in reality it was because they were highly concealable.
Typical grabber BS. If they wanted to ban concealables, they could at least have debated that point head on. Instead, they lie and call high-quality (but small) arms "junk".
Bastards.
Anyways, Ruger SAs plus the various Italian SAAs, the current FAs all come out fine. There may have been a Cimmaron variant with bird's-head grip and 3" or so "Sheriff's Model" barrel that might come in under the 7.5" overall length rule but if you bought the same gun with a 4" tube and had a gunsmith cut it down, you'd be OK. Likewise, it may be possible to build a short-barreled Vaquero with bird's-head on a gun you own that comes out shorter than 7.5". Still OK to own it, but if you sold it to a dealer, he couldn't sell it in-state, he'd have to sell it out of state.
You couldn't buy a Gary Reeder customized mini-Ruger (2" barrel, really short bird's-head) from him on a gun he bought and built up. You'd have to buy a full-sized gun, ship it to him, have him send it back shrunk.
Jim