Is there a way to tighten the convertible ragtop to eliminate leaks and a mildew smell?

 

First you need to determine where it is leaking, if it is in fact leaking. The smell may be coming from the A/C system, which has nothing to do with the convertible top.
If the top is leaking, you need to figure out where it is coming in and fix that leak. It's not just a question of "tightening" something.
There are channels built into the system to allow water to drain out. If one of those is plugged, the water may not be able to drain properly and it may be getting in where it doesn't belong.
Have you noticed wetness inside the car? If so where?

 

A common thing that gets clogged up are the drain slots in front of the wheel wells on the bottom. Use a screwdriver to make sure these are clear. If they get clogged you will get water inside. It's good to check them if you never checked them before.

 

thanks much for your time