Nick,
Solo wins are always something to be proud of, seeing as how many games bog into a stalemate... This isn't anything surprising - if there is a clear front-runner then the rest of the board usually gangs together to try to prevent them from winning. A 22 center win in 1906 is definitely very cool.
But I don't think we keep records of this stuff in DC. The Hall of Games is there, so I totally recommend poking through it and checking it out.
Comparing one solo win to another is like comparing two flawless diamonds. Each is stunning in its own way. Imagine soloing an Imperial game, with a minimum winning condition of 70 centers. Or soloing in one of Sims FOG games - where you can't even see the entire board...
In one case, I saw a Germany convince the rest of the board that he deserved to solo even though he only had 12 centers. Nowhere near victory conditions - yet he persuaded the entire group of players to agree to it. It was a brilliant piece of diplomacy.
Anyways, just my two cents worth.. Cheers,
Trout