'81 300sd - Rear Sag Question

[mhuggyberre]

Question is simple. I am new to this car and am slowly falling in love with it and want to fix the small issues I have with it. 1st is that rear sag. The car doesn't bottom out and feels smooth so I dont really feel I need to change shocks so what can I do to lose the sag?
Also, while I'm here, does anyone know much about fixing the vacuum issues with the door locks? I also have some transmission gear change smoothness issues. It isn't rough but when she's cold, I need to either be real gentle with her or decrease the amount of fuel she's getting before a shift change so it doesn't seem so sudden or noticeable. Anything I can do about that?
Any help you can give will be greatly appreciated.

Mario