These are vintage K&E Planimeters model 4236. 1930s - 1950s. The number 61279 is a serial number, not a model number. This is a mapping device that is moved around a irregular perimeter to calculate an area. They are missing a 2nd arm which is pinned to a fixed point to create a "Polar Planimeter". The other parts may not be related. They may be part of an adapter attachment to convert it to a "Linear Planimeter", but if so, they are not complete either, there should be wheels.

These items are planimeters. There are two of them in the photographs. They were used in measuring areas of irregular shapes on maps or drawings. They are pretty much a museum item nowadays with computerized mapping.

References:

https://computarium.lcd.lu/photos/albums/OTT_Polar_Planimeter_49539/album/sli...

https://en.wikipedia.org/wiki/Planimeter

Reason:
Another opinion was accepted instead.

These are vintage K&E Planimeters model 4236. 1930s - 1950s. The number 61279 is a serial number, not a model number. This is a mapping device that is moved around a irregular perimeter to calculate an area. They are missing a 2nd arm which is pinned to a fixed point to create a "Polar Planimeter". The other parts may not be related. They may be part of an adapter attachment to convert it to a "Linear Planimeter", but if so, they are not complete either, there should be wheels.

References:

https://www.ebay.com/i/202795397736?chn=ps&norover=1&mkevt=1&mkrid=711-117182...