Fussy, I think you deserve a medal!
My dd refused solids for a long time, and still, at nearly 12 months won't eat anything lumpy. Mind you, she only has 1 tooth, and so can't chew very effectively.
Have you tried going back to the "4 month" desserts? My dd loved Hipp Peaches and Honey and Dutch Apple Pudding- they are both really smooth and very sweet, she would eat them when she would eat nothing else! You could then move from desserts to savoury, and from there to more lumpy food over a few weeks.
Another thing that occurs to me is that he may not be hungry, if he's getting all that milk day and night, maybe its time to cut down on the breast feeds a bit. My dh misunderstood some instructions the other day, and dd got 6oz more EBM than she usually gets while I was as work, and flatly refused to eat her dinner. Not surprisingly she was starving next morning.
Got to go now, may post a bit more later, but I'm sure other people will have some ideas.