Just my two-cents but I would leave it as is. You will destroy any collector value by messing with it.
Also, if you go to the expense of restoring it, what do you have? A mechanically inferior pistol (i.e., safety features, etc.) in a mostly useless caliber.
Unless there are strong sentimental factors here, I would leave it as is.
(PS... Would be willing to bet that Colt will not touch it.)