Okay, it's looking better for the Summer SEE.
Checked the strainer and there was very little black crap in the bowl. Pulled the drain plug on the tank, and while the hollow part of the plug was full of crap, that was about it - no noticeable debris in the fuel that came out. Looks like Bio-Bor and the frequent strainer cleanings are starting to pay off.
For what it's worth, peakbagger, I don't bleed the filters after cleaning out the strainer. I see no need to.
By stopping the engine before it runs out of fuel, which is easy enough since it gives plenty of warning, the only air introduced into the system is what the strainer holds. That's maybe 4-5 cc.
I used to fill the strainer with additive from a bottle, which was the easiest, and bleed. Then I noticed that the times I didn't have the wrench to bleed with, it made no difference, so I stopped doing the bleeding procedure.
Then there were times when I didn't have the additive and just put the empty strainer cup back on. Again, other than a barely noticeable hesitation after a while, as that small amount of air had made its way up to the pump, it ran just fine.
I'd guess that the constant air supply from the leaks in the lines that this SEE used to have was far worse for the pump than getting an occasional dose of air from the strainer.
Of course, trying to start with a system that's full of air, without priming and bleeding, would explain why General Hood sold his starters so quickly.