The original file by @Blende8 was great, but you had to use clamps to hold the solar filter in place.
This remix resolves this issue by using the same method other solar filter holders are using.
A ring within the Plate holds the solar filter tight in place.
The author remixed this model.
This remex added a ring to the Filter Bracket and resized the hole in the Cover to fit the new ring.
With this change, the Solar-Filter (Baader or similar) can easily be attached to the mount and you don't need to screw it or use other brackets to hold both peaces together.