In that case, it may be even easier to rebuild distributors then!
Simply leave the bottom screw alone which will keep the barrel locked in the same place at all times -- You could then safely separate the two halves, clean and backflush the micron filter and replace the 6 o-rings (removal of the o-ring down in the barrel would not be possible though), apply gasket sealant and put back together.
OR, remove the barrel completely line it up and tighten the screw before putting the halves back together. I may need to separate mine again now....
I think we are slowly cracking it...
I enjoy posting photos as they really do say a 1000 words and for future reference it is a great resource. You never know when the photo of an engine may provide information for future repairs, or position of items etc...they are invaluable in my mind. I have probably 5-6GB of photos stored now on my server over the last few years. I always save uncompressed ones too since you never know when you may need to zoooooooom in