Beautiful 911. Love that you have driven it 600K miles over 45 years. I too come in on the side of mechanical, rolling restoration. Unless there is rust and body damage I would not touch the paint. If it needs new rubber seals, interior, do all that. I would do full suspension restoration, brakes, all lines and hoses and complete engine/transaxle. That car has given you 45 years of terrific service and deserves to be treated to a refresh. Have fun and good luck. Oh, yeah, please post pictures along the way.