The cyl in my Bisley will...left-right, up-down and fore-aft. I don't have another S.A. to compare to. Just how much wobble is OK? Or should it just rotate on the pin? The play, in my opinion, is just a tad more than 'perceptible'.
I'm with Joe, the proof is in the accuracy, seen some "loose as a goose" and shoot awesome..............its when accuracy goes, or spitting ( blow by) misfires, fail to lock up, throws by ,etc, then one must look into the guns lock up..........
The condition you are concerned with is the situation when the hammer strikes the firing pin, pushing it into the primer and igniting the cartridge. At this point in the cycle the hammer is "full down" and the trigger is "full back" and neither of those have any bearing on the lockup which is at that point of the cycle entirely under the control of the bolt. Since the hammer is "full down" the pawl has completely retracted and is not holding the cylinder against the bolt, so it's the bolt fit alone that's determining the alignment of the chamber with the bore, along with the base pin fit.
As mentioned above, the proof is in the performance. If the gun works well, the parts are properly functioning. There may be a little "play" in the cylinder at the exact time of ignition, but if there's no ill effects, it's not a problem.
Another plus side of going to an oversize base pin and attending to end play of the cylinder is that it helps smooth the action of the gun while the cylinder rotates through it's cycle.