Breguet seems to refer to the movement inside of the Classique La Musical as both the caliber 777 and 901. It can't be both, but I suspect it is the 777. The 901 may be a base automatic upon which the music functions are built. The movement is actually an automatic - which I found surprising given the fact that it needs a lot of space for the moving music box disc and blades. It operates at 4Hz and has 45 hours of power reserve with the sound function turned on (55 without). A pusher allows you to activate or deactivate the alarm function. Though with it on you'll probably need to still manually wind the watch a lot. You have to expect that if you wear a timepiece such as this you are going to play with it an awful lot.
It sounds like you are asking if polishing your watch during servicing will affect its value. That is a good questions and highly subjective to the collector. If you want to preserve the value of your watch as vintage, then polishing is not recommended. The same goes for replacing anything visible - hands, dial, bezel. A full movement service, on the other hand, is an excellent idea.Read more ›