Gday Scotty,
Looks like I'm not the only one delving into the deep guts.
Behind that screw (the one near your timing bush) is your anti wet sumping valve which appears to be the cause of much grief and smoke.
http://www.a7a10.net/forum/index.php?topic=848.0ps. for interest only - its no longer for sale. I think fido ate it along with one of my new sludge trap plugs.
I bought a new spring & ball bearing thingy from the UK. The postage was more expensive than the item which I was disgusted with.
I can get a better quality spring out of a biro. It takes a hell of a lot of effort and money to get to this deep into a motor and I would have been happy to pay 3 times as much to get a decent stainless spring rated for the job. The plug is not easy to get out. I drilled a few 1/16" holes in line with the slot, flogged a screw driver into it and wound her out. Guinness helps.
Scotty, take a mugs advice and change that valve now that you are in there.
and If you find someone who sells a decent spring, please let me know.
cheers