Getting your hands on a copy may be a long shot, but Shadow Over Bogenhafen from the old WFRP system is a swell adventure. It will require more drastic rules conversion than even Diaglo's golden oldies, but it's a sweet adventure.
The Banewarrens has some interesting city scenes and detective work, but there is one heck of a dungeon looming over the adventure. This may or may not work for you and your players if a complete retreat from the dungeon is what you were looking for.
I can think of no one better to recommend forgotten, old school adventures than Diaglo. Most of them sort of stunk, so its invaluable when he can recommend the good ones. I have been looking at an old copy of B4 Lost City, but unsure if I should pick it up, what with the aura of stinkage and all. Now I know that it has Diaglo's seal of approval, I think my path is now clear.
I think we should be nice to Diaglo, or he'll just go back to the thronging hordes at
www.diagloworld.org, on the D&D/White Box Messageboards, and leave us behind. How else will we be able to gather at his feet, and learn how you had to carve your own d20's out of soap in the old days, or what it was like to find out about drow the hard way rather than in character creation? Diaglo takes us back to the golden age when men were men, halflings were hobbits, and orcs guarded chests in tiny rooms. Plus, he's been at this 10 years more than me and keeps me from feeling like an old fart.