"Tweaking" 1987 300SDL - 175k

[ehm]

I recently acquired an '87 300SDL. It has 171k on the clock, which has stopped working, but I have every reason to believe it still only has about 175k as I use the same mechanic that serviced the car over the years. It sat for several years (4?), with very infrequent driving - not tagged during that time so pretty infrequent I imagine! I have replaced all the 'engine compartment' fuel filters, of course oil change, and some other parts such as calipers all around and lower brake lines, and tie rods, 1 of which were definitely bad. It runs great and just seems to keep getting better. And the mileage seems to be getting better but it is still less than 25 I think, and it seems it should be better. Also, in town, especially if not driven in a week or 2, I see more smoke from a takeoff from a light than I'd like or expect. Are there relatively simple things I might check, perhaps like some type of air/fuel adjustment etc? I had a leak on the return fuel line and fixing that definitely helped! Thanks as always.