The contents of the folder reveal how the first working oscillogyro created by J W Barnes was modified to incorporate capacity pick-offs and torquers, and to try out the Ferranti patent suspension elastic hinge for the first time, recorded in design sketches of 28 September 1964.

The majority of sketches in the folder are the carbon copies of Designs Department sheets and record to whom D W Alford sent the sketches. Also included are rough sketches and notes to be read in conjunction with final reports (the AELB reference for each report is provided). There are two diazo copies of schematic drawings loose at the front of the folder.

D W Alford has written explanatory notes to the folder on its front cover, noting that its contents supplement the Day Books catalogued as 2022-235/3/2-4.