From the research I did this appears to be a brass Antique engineering, surveying transit level spotting scope by W and LE Gerley in Troy New York dating back to late 1800s. Possibly as far back as 1860 from what I could find on the item.

It measures approximately 20 inches long to a quarter inches wide.

It does have a dent on one end. See pictures also is missing two screws for the tripod mount.

The adjustment nearest the IPP seems to have gears, stripped it does still move and adjust with help as you turn the knob. It seems to work otherwise. There’s also normal wear and tear feel free to ask questions. I will try to answer them as best I can.