My solution was the same as Personman's, except I completely forgot about Mining village. Huh-durr!
1. Village
2. Watchtower
3. Bridge
4. Bridge
5. Throne room
6. Throne room
7. Throne room
8. Great hall -> draw village
Village -> draw watchtower (last ironworks in hand)
Watchtower -> draw 3 TR, 2 bridge
TR -> TR -> bridge
-> TR -> bridge
-> ironworks -> province, drawing great hall
-> harem, triggering reshuffle, drawing harem
play harem, buy colony @7 w/4 from bridge, 1 from ironwork'ing harem, 2 from harem.
So you actually could make the puzzle a little more cute by requiring that you end up with a colony, a province, a duchy, and an estate.