Hmmm...it might be tough, but you might try removing ANYTHING from the table that could be a distraction. Does he want to look around throughout the whole meal, or just at the end? If he's distracted after he's been sitting there for awhile, that may be his way of telling you that he isn't interested in eating anymore. I don't think you're wrong to end the meal at the hour mark, that's more than reasonable. If he isn't upset when you end the meal and isn't showing signs of still being hungry, he may just be taking his sweet time. I've heard of people having success doing it this way...their LOs learn to pick up the pace a little by realizing that mealtime doesn't last forever.
That said, Tyler used to be a pretty slow eater. I just went with it and ended the meal when it was clear that he was more interested in doing something else (he usually started throwing food, so it was pretty obvious). He grew out of it as he got more proficient with finger foods, but he still has the occasional meal where it takes him an eternity. Hang in there!
