Hello,
Very important to service a Perpetual via Patek only..... the watch will need 20+ replacement cogs/wheels/small parts...... only Patek has access to this inventory.....
Using a 3rd party independant is ok for a stock Rolex or simple Omega...... but with a very complicated Patek..... only 1 answer...... TAKE IT TO PATEK!!!
If you don't wnat to invest such money you could always put the item away in your safe.........