All's well that ends well.
I swapped in the same 1447 bulb that lights up in my 681, and it didn't work in the 682. I then tried a used 1447 from my miscellaneous junk box, and it worked. Returned the previous bulb to the 681, and it lit up like it should. This electronics stuff is all black magic to me, but problem solved nonetheless.
I then carefully dabbed some so-so strength glue onto the rivets (found the one that fell out) and pushed them into the shell. After waiting a day for the glue to dry, I primed the smoke unit with drops and let 'er fly. Thick, beautifully-defined O's once again billow from the stack even though I did NOTHING but take apart the smoke unit and inspect it. I did note that there is no donut-shaped gasket between the top of the smoke unit and the body--does this matter and/or affect performance? The 682 and consist have now gone 50 laps around the xmas tree oval without a hitch--it's a Christmas miracle!
I am leaving well enough alone, but my next question: which position for the side linkage is correct? Elbow "up" or elbow "down"...?
