Help to Identify this floor spring?

Is there any one out there who is able to identify this floor spring and willing to share this information?

Below are shots taken from beneath the brass decor plate.

I do know the floor spring was sold by Comyn Ching in or around the 1940's which ties on with the buildings age, built in or around 1935/6.

I suspect these were supplied by John Nicholson furnishing ironmonger and manufactured by Smith and Turner but do accept I may be well wide of the mark on this occasion.