Lockback problems on 1911 22 conversions

I have 2 units. An original Marvel which was changed to a steel slide, and a Bob Marvel AA. I have 2 steel mags and five plastics. The Marvel worked OK w/ one of the steel and the plastics for MANY rounds. The AA never. The Marvel has the original slide lever modified so a screw holds the 2 parts in place. The original screw was lost and the replacement works w/ that one the steel mag if the screw is adjusted just right. The AA never w/any of the mags or either of the slide stop levers or the 2 dedicated frames. 

Marvel says their best results are w/ their current slide stop levers. I haven't tried that as of yet as the slide stop is not being pressed very high in the slide stop notch. Considering that I'm not confidant it might work. Also their desription of their unit sounds a lot like the AA which won't work in either unit or frame.  

Right now I'm considering silver soldering an extension on the slide stop.  What experiences are other conversion users having and what renmedies have you found?

Thanks for any help that may be offered.

Ron