Steve,
Just for the record, one cannot braze anything, silver or otherwise, anything that has already been plated. Polishing can ce done in advance on some parts but the finish polishing must be done after the frame is complete and before it is handed to the plater.
Plating of chrome itself is not done in multiple layers. If multiple coats are required copper is first to go on and only if neccessary these days. Most chrome operations only require nickle first, then chrome. They go into each plating solution only once. The druation in each tank determines the thickness. The majority of plating is nickle; the chrome is very thin over the nickle as a rule. One wants to avoid surface tension on chrome the same way as on paint, it one wants the best results.
Hope that clarifies the plating basics of chrome frames.
Brian Baylis
La Mesa, CA