I wouldn't change either Servoguy if it works then it works. I have seen recommendations of checking engines that run each year and those that sit every three years. So is there a best time or schedule? I guess there is but nailing it down to an exact is probably harder. My only real point is to make sure they are lubricated and I don't think for the most part the brand is all that important. I certainly would consider using plastic compatible lubricants though.
I do check any engine that has not been used in a year prior to running it along with all new purchases. Then I also check grease my daily runners each year. Thus an engine that is not run may go for a few years without being checked.
I should have been more clear when I said check them every year above.
I can't tell you if this is correct but it works for me.
