I finally got around to pulling the tank strainer. I fully expected it to be clogged because the car sat for two years before I bought it. It was completely clean (see post #9-thanks, Jay!). The fuel I drained was very murky but had very little particulate matter when I strained it. When I went back to examine the particles from the little filter, I found that they will MELT upon application of heat. Now I'm guessing that I'm prey to wax precipitating when diesel and WVO mix. I had been adding 100ml of naptha per 5 gal of WVO/RUG blend to prevent this, but no dice. I'm going to try mixing dino and my blend in the old garage lab to see if I can duplicate this.
BTW, for those who have access to large standard tools, a 1 13/16" substitutes nicely for the 46mm needed to remove the tank strainer. Not that I would EVER recomend anything but the correct tool properly applied.
Thanks for the use of the facilities, Jay!
Scot