I found this cool Third Hand from Hobby Creek, which is doing a great job to fasten objects for soldering. It only lacks a magnifier. The stand of the Third Hand has some more holes which could be used to add another arm with a magnifier. A complete set was not available, so built one myself. I bought this set of arms and a magnifier with battery driven LED light. The magnifier should be removable. I used Polymorph Thermoplastic to build a mount where the magnifier can be inserted. The thermoplastic was also used to attach the mount to the arm.
Quite simple but very usefull.