Updating an Accutron Spaceview

I have a 1967 Spaceview that will not run properly with modern batteries. From the web I have learned there are a number of people who fix this problem, but there are a number of approaches. One is to replace the innards with newer parts; I do not want to do that. Other approaches involve putting a resistor in to fix the voltage level. I would prefer the latter, but am hesitant to send the watch off without having some independent references as to the honesty and quality of the repair person. Does anyone have experience with this?