Check this out, found after a quick google search:
https://forum.cyclinguk.org/viewtopic.php?t=42229
Includes this reply:
"Your Enquire about C Bertrand And Co interests me as the company in its later days was owned by my Father, and mother in law Edgar R G Sage and Winifred Sage.
They purchased the company and property, 654-656a High Road Finghley N12, in, or around 1947. Edgar continued to manufacture cycles well in to the 1950's, but by this time was unable to make a living simply from Bertrand and Co,so he therefore found other employment continuing to make bicycles part time.
By the time I met my wife Carole ( their daughter ) in 1960, Edgar was again running C Bertrand and Co full time, but mainly selling and repairing Motor Cycles, and Scooters, pedal cycles by this time were a very small part of the business.
We still have a Bertrand cycle, and an experimental Tandem in our barn, both in need of serious referb' the cycle is complete, but the tandem is minus wheels.
Should any of this be of interest to you, or you want to clarify any points, please come back to me."
And this link:
https://pedal-trikes.blogspot.com/20...and-trike.html