First hope you will enjoy your new aquisition. Suspect your problems are relatively minor. Rather than changing to longer glow relay etc just check your current glow plugs as you may just have a bad one in there and as winter driving is not contemplated they usually start and run fine with the normal system working properly. At least my 82 does. Find it is really helpful to use the high idle setting to start on with both my 240s. The next or first thing is to check your valve settings as you mentioned before trying to set up idle a little. But again if you find a bad plug or valves really out of spec. idle adjustment may not even be required. A can of diesel purge would not hurt either in my opinion in fact may be helpful. The general state of the air filter may indicate if the last owner cared at all about car. Anyways I really enjoy my two when i get time. Edit: sorry for the partial duplication pelang as I was typing a response while you were posting I guess.