Plumb Bobs on Roman Republican Coins

I recently purchased a plumb bob from a site that normally sells ancient coins. The piece was described as, "Roman bronze bilder weight II Cent A.D." I am an engineer and thought the pumb bob would fit in well in my office.
About the same time, I saw a coin of L Papius, Cr 384/1, that used a plumb bob as a die marker. The plumb bob on the coin looked nothing like the one I bought. The symbol on the obverse is a plumb bob. The symbol on the reverse is a Roman Level with a plumb bob in the center. Place the A frame on a wall and the top of the wall is level when the plumb bob hits its mark.

I did a bit of looking on line and found a plumb bob web site run by Wolf Ruecker, or Plumb Bob Wolf - plumbbobcollectors.info. Turns out mine is an Ottoman plumb bob. Wolf was interested in the plumb bob on the L Papius coin. I said I would look for similar die markers. I found them on two more coin types - M. Volteius Cr 385/3 and Cr 385/4, see below.

Triton IX, Lot: 1291

British Museum on line 

I found another level on a coin by M. Plaetorius M.f. Cestianus, 67 BC, Cr 409/2. The coin is in the British Museum. They have not identified the symbol. I sent them the note below suggesting they call the symbol a level.

British Museum on line

Hello from El Lago, Texas.

I have identified the symbol on your roman Republican coin: 409.2.42, a Roman Republican denarius of M. Plaetorius M.f. Cestianus, 67 BC, Cr 409/2. The symbol is a Roman Level with a plumb bob in the center. An example of the level on your coin and in a picture is below.