Went to the range today to do some plinking with a Ruger .22 pistol.
Not a Standard Model/Mark I, not a Mark II, and not a Mark III, but...
The thumb safety is a more conventional pivoting one, and the right-hand side of the ambi safety (if you aren't one of those people whose right hands are on the wrong side) can be removed with household tools, if so desired.
Then the upper assembly lifts off the gun, the bolt group is pulled out the back, and you're done. The gun can be disassembled for cleaning and put back together again in less time than it took me to type this paragraph.
There were a bunch of them on hand and I didn't personally see any malfunctions, but you expect that with Ruger deuce-deuce pistols.