@ColBosch: I have some purely gratuitous advice which you might cheerfully ignore (or, more probably, are already well aware of), but which might be interesting to you as a source of ideas for little side adventures (and to other folks, possibly, as well).
Go to CR Brandon's
web page and check out the "free downloads" section. He's got a couple of mini-dungeons in there that would do very well for some "appetite whetting" and can easily be used as minor lairs for the bandit types in
Tollenkar's Lair. They might save you some time trying to figure out some mini-dungeons/labyrinths of your own. I suggest downloading Cauldron issue #0 as well, it's got both an adventure, and a methodology for converting D&D stats to HOW (which is practically the same as converting them to classic TFT). Unfortunately, it appears that he's removed "Esur the Red" from his library of free downloads, and that's a shame, because it had a random burial mound map "generator" that was pretty cool... (Of course, if you have
Barrowmaze, you have something sort of similar you can use.)
Of course, Dyson Logos'
web site is just chock full of very useful maps (one of which -- so far -- is actually done in TFT hex format!). He's the guy who did the battlemaps for Legacy Edition, so you already know what his work looks like.
Also, over on Dark City Games'
web site, they have a couple of free adventures to download; one of which is against a band of orcs in the mountains (possibly useful for additional clues) and the other of which is an exploration of a Sorcerer's mansion (which could be a possible escape location for Tollenkar if you want to preserve him for later use...). They also have a couple of free adventures for their space version of TFT, but those probably won't be of much use!