Lee, know you are 74 but then again there are 74 yr olds and 74yr olds. Guess I am just a young fellow at 63 this year. If the rough idle bothers you I would consider scribing the pumps position and try a small movement towards the retarded side. If that works out to smooth the idle and you still have pretty good acceleration thats were I would go. Some merit once in awhile to setting a pump timing position by ear. Before you move the plate again on top of injector pump do a drop in rpm test on the #1 cylinder and compare it to it's neighbour. That in my mind is the best way other than taking the pump to a shop to get it reasonably close compared to the other pump elements. From your description and other things. There might be an indication that the pump overall might be a little too far advanced. With the scribe marks on the pump and it's flange there is no chance of not being able to return to the present position if idle does not smooth. Also one other other thought. Assuming the rebuild 60k ago was done basically properly inside the block and compression across the board is assumed pretty even. Did you at any stage check the valve clearances? All this of course after you do the italian tune up but suspect that is not going to make too much difference as you purged the engine not many miles ago I thought. But I have been wrong before.