There is some good here. At first, the mission feels pretty decent. But it quickly fades. Some technical problems I encountered:

As in most missions, each step of a stair case is hand crafted. In this mission there are multiple rather large seems as a result of not aligning each step properly.
Torches backwards and not snapped to grid.
Long stretch of areas using one (and the same) texture for floor, walls, and ceiling
Carpet placement too high so its surface is counted as stone/tile in the wrong places.
Almost every door and chest is locked with a complex lock (needs to swap lockpicks 3 times).
Pet peeve: complex lock on outer door AND every single chest in the room. (and why are we locking empty chests?)
Sound brush errors (can't hear picking locks and guards right by you in some cases)
Completing final objective killed me. Had to reload and creep slowly into portal so the mission could complete successfully before I died.
Lots of room brushes visible in the walls were they weren't snapped to grid.

There is also lots of backtracking in a very bland, mostly single texture mod. I give it points for some originality. There is an effort to apply audio ambiance, clues in books, and some thought put into guard patrols. There are a few moments of good architecture and level design. There is some nostalgia knowing that "back then" this was all we had and it was fun to get some extra Thief, but unfortunately, some of the errors that are easily fixable are glaring and reduce the fun.