There are two "family's" of the Ruger .22. The old, original version, that has 3 screws in the side of the frame. They also have the half-cock feature, to load/unload. Some of them have been sent back to Ruger to be fitted with different internals, so they can be safely carried with all chambers loaded. Then there is the New Model, that has two pins, crossways in the frame. They have no half-cock, and are loaded/unloaded by simply opening the loading gate, which causes the cylinder to free-wheel. Prices vary quite abit, depending on what version you have.
Both "Old" and "new" came with the sights you mentioned, where the rear is drift adjustable only. They are known as "single six", though some refer to them as "flat-tops" ( not really correct ).
The version, old model, and new model, with fully adjustable sights, is called the "super single six". It would be an expensive, custom, job to convert yours to fully adjustable sights.
With the two cylinder versions, know as "convertables", each cylinder should have the last 3 digits of the serial # on the face of the cylinder, by electric pen ( etched ), if they were provided by the factory.
In any event, whatever version you have, you've got a rugged, dependable revolver. Price seems good, too. Post more with exactly which version you have.
Mark
