They are overbuilt rugged dependable,guns designed to be put in the trunk of a police car, pulled out when s@%t hits the fan as a cannot miss carbine at ranges beyond pistol .I shoot mine at 50-100 yards all the time. It is a fun plinker. The trigger is stiff...but not too bad. Mine is VERY accurate.
As far as rust goes....mine looks brand new inside, I mean the build quality is astonishing.. I am not at all sursprised that you could submerge one in water , wd40 it, then use it again.
Ruger must have lost a lot of money making these. they only built approx. 20,000 in 9mm and 15,000 in 40cal. (over a 10 year period!). The ironic part is everyone wants one now. They can share mags with your P series pistol and travel together . Indoor shooting ranges will let you use them too because its a pistol round!
I am not interested in selling mine either, if i were looking ,I would try gunbroker or gunsamerica.com. If no luck, then i would get a Beretta storm carbine. (They are just as nice)