Hi Bruce!
Boy, If I were you and faced with this dilema (Who isn't when we're over the age of 45 plus?
), I'd go for the tang sight and give it a try. You will find also that if you are wearing eyeglasses that by using a piece of black electricians tape over the eyeglass lens with a small peep hole in it, you will dramatically improve your depth of field. It will take a little fussing to get it positioned correctly (when you get the sights lined up), but the cost is nil.
Hope I helped, and keep looking for that Stith mount and scope. It would be such a God Awful shame to ruin that ole beauty! Check out eBay and the Savage collectors site.
Jim