I worry about the stopclick also and either of the winding/reduction wheels 1480 and/or 1481 if there is any load on the mainspring prior to removing the 1142 bridge. These parts are hard to find and expensive now. As for the balance, balance bridge, pallet bridge and pallet - I clean all of them in One Dip which has always worked great. Cleaning the balance jewels is also my least favorite project on this movement, especially the cal 15. These Buren movements are an odd design to say the least and it is amazing to me that they have survived as long as they have.
Thanks for your response and good luck with your watchmaking in the future.

: ..in few words you are correct, I don't know a way to unwind the
: mainspring before dismounting the 1142 bridge, and if you open
: the click 425 with a well wound mainspring you also risk to
: damage the delicate stopclick 1428...so I wind down the
: mainspring only after having dismounted the 1142 bridge.

: Best.

: Gianluca

: Hi Craig,