The Heroes Round Table

Possible... with the MM6 party I did have fly, but did go through the teleporters anyway.

But the two games I mentioned in the parenthesis were played with the merge mod.

You still have them after activating the teleporter?
In my game the stones disappeared by themselves upon activating their respective teleporter (both for a MM8 party and a MM6 party that teleported over to Jadame).

If you use the Invisibility spell they will not turn hostile and you can take whatever you want from the treasury. Though the automatic message that warns you back turns off invisibility, so only cast it after the dwarves tell you to turn back.