Shockstop produced these in the late 1940s for use on brake levers to cushion the riders hands when using brakes such as the GB Hiduminium, especially when working hard ('honking' for the British riders) up a hill.
The originals are extremely hard to acquire, and all attempts to find some reported reproductions were unsuccessful.
Mario aka 'Silverlight' said he had an original set.
He generously loaned them to me to measure and try to have them reproduced.

The rubber has hardened and has splits. It is unlikely to survive installation onto the brake levers.
After exploring various methods of making a master, we settled on a aluminium version. A mate machined it for me.

I identified the font, then in a series of steps in Illustrator, arrived at the desired single stroke, and ensured the kerning closely matched the original. This provided the path for the engraving.
But finding someone to machine the text around the master was difficult. It is not often done nowdays and the pantographing machines and skilled operators around immediately following WW2 are long gone. A local business was willing to try, and it took three passes on each side to achieve the required depth.
Another local business was confident to make the reproductions and after making the mold from the master, a number of compounds were trialed to achieve the combination of being able to be installed, being durable in use and providing the required level of cushioning.
A small production run, at one per day, was commissioned.

There are sufficient differences to allow no confusion as to what is an original and what is the reproduction, and that is desirable, starting with the use of a modern compound and not rubber.
A special set was made for my Spearman.

PM me if you are interested in a set for a late 1940's bike.
GB introduced the Superhood brakes in the early 1950's and these incorporated rubber cushioning to the brake hoods, negating a future market for these 'honking' rubbers.
It has been a satisfying journey, particularly this afternoon when I was finally able to provide a set to Mario, as a token of my thanks. Great forum this!
I hope this inspires others.
Philip