Looks to have been very little used with all original finishes. I have not cleaned this at all, it is exactly as found. The brass is a beautiful coppery color. The dovetailed mahogany box is in superb condition and has the original stamped leather strap as well as three original paper labels intact as shown in the photos.
The tray that the transit sits on is also stamped 'BUFF NO. 7999' and included in the box is the original plumb bob and lens shield plus a string reel of some kind possibly for the plumb bob.
The box has the original Buff & Buff brass nameplate as well. The faceplate on the transit reads 'BUFF & BUFF MFG CO. BOSTON 7999' and 'MODEL NO. 21 PAT'D NOV 13 1900'
The best one I have seen.