1986 300SDL turbo, 6 cylinder, 126.125, 603.961

My local Mercedes dealer told me it would cost upwards of $1200 dollars to change the timng chain. I don't know if I need a new one or not; I had called to make an appt. to get it checked out--the car is idling slightly roughly.

I can't really afford that much for a fix I don't know I need (the tech said there is no way to check unless you pull the engine part, and once in you might as well do it anyway).

So, my darling boyfriend who maintains the car gets to do this. He has all the service manuals, but I do need to know the exact tools necessary. I found a great site that sells MB tools: www.skywaytools.com, but they use different names than posts here.
So: is a "Locking Nut - Injection Pump Cam Shaft" necessary? Is the "Adaptor bit" the same as a master chain link pressing tool? And what is the tool necessary to get the old chain off?

I appreciate any help.

Thanks,

Rachel