Thanks guys, I think you're right, I'll give it another go with the Simple Green. Now that I know I don't have to pull out the drum and shift forks I really don't want any abrasive material getting in there.
BTW, heard back from Lyn at Vintage Specialties - the crank is junk. It was so far out that he couldn't even get it close. Fortunately he has a rebuilt unit already to go. So for the regular cost of the rebuild plus a core fee it should be on it's way back to me shortly.
Also was doing some more reading on different forums of rebuilds trying figure out all the little tricks that don't show up in the Hayne's manual. It's seems like a pretty simple engine but like everything, you need to be organized and not tear into it blindly, e.g. I'm really glad I didn't attempt to diasassemble the oil pump before I did some poking around!