W H S Kingsway Postcards

[eastlondonpostcard]

Does anyone know when WHS (WH Smith & Son) stopped producing their famous Kingsway series of postcards? - and is there a connection with Bridge House postcards?
Any help appreciated please...

[eastlondonpostcard]

I now discover that 'Bridge House' was purpose-built by W H Smith to house the Bookbinding Works and Stationery Department, Lambeth London.

[Wolstan Dixie]

I would like to know that and their starting date; but also WHS Kingsway must have been a HUGE operation, on the scale of Frith or Valentine - *what happened to their negatives* (presumably glass plates)?

Certainly HHH (in a triangle) postcards are the same images with the same numbering as Kingsway, but no other branding. I get the impression Kingsway sold off old tranches when the took a new one (for example Welbeck Abbey, which I collect, was photographed in 1908, 1910, 1912 and 1913

[eastlondonpostcard]

I would like to know that and their starting date; but also WHS Kingsway must have been a HUGE operation, on the scale of Frith or Valentine - *what happened to their negatives* (presumably glass plates)?

Certainly HHH (in a triangle) postcards are the same images with the same numbering as Kingsway, but no other branding. I get the impression Kingsway sold off old tranches when the took a new one (for example Welbeck Abbey, which I collect, was photographed in 1908, 1910, 1912 and 1913

Their start date is uncertain as with many companies, but they were in full swing by 1906... according to my 'bible' : Picture Postcards & Their Publishers.
They were certainly producing their Kingsway series up to WW2 I believe. Did the Bridge House series take over?