Looks like I see a stone saw tool (ropes with handles) on the far right of that picture, similar to what you mentioned earlier. Is that specifically what you were referring to Questionmark?
I'm not questionmark but would like to weigh in. The wooden handles with the cord could just as easily be a simple device for determining the level and smooth surface of a block of masonry. It sounds kind of odd but this is attested in inscriptional material on relief carvings or paintings on a tomb wall. The exact tomb escapes me but I believe it belonged to one of the noblemen on the west bank of Thebes and dates to Dynasty 18 or Dynasty 19. It's altogether possible more than one tomb has such a depiction.
In any case the two wooden pegs were held wide apart so that the cord was taut between them. The cord was then run down the surface of a block of masonry. Wherever the cord bulged out, the mason would set to work to smooth that spot.
As for the vampire stakes, you've correctly identified them. Vampires were a big problem back in those days, so while the guards patrolled the necropoli they carried these as part of their weaponry. You know those vampires and their love of cemeteries.