I have seen many of these clocks at auctions, all from the UK. They all seem to be similar in design.
These styles of clocks are my least favorite! For the most part, the movements are average. They seemed to have been a trend in the UK throughout the 1930’s & 40’s.
Photo of movement similar to those found in mantle clocks such as Smith Enfield.
I have a preference for ‘functionality’ with clocks that I collect. The whole point of the ‘long-case’ clock was to accommodate the weights that slowly descend to the floor.
These clocks are generally fitted with spring movements similar if not exactly the same as those in mantle clocks! No weights and short pendulums.
The floor standing case is simply an aesthetic stand for a mantle clock movement. The only function the case serves is to enrich the chime that is produced by such a large sound box.
Due Time 
I’m a little confused. I have a smith grandfather clock marked smith made in gr britain enfield clock co. It has weights and a wrought iron plaque that
reads GREAT BRITAIN GONG. The front plate reads tenfus fugit and
to the left it says silent chime. Did I misunderstand your description or is mine older? I HONESTLY AM TRYING TO EVALUATE IT AND IF YOU CAN PROVIDE ANY INPUT THIS WOULD BE TERRIFIC. THANK YOU SO MUCH.
Hope this helps:
http://www.smiths-clocks.co.uk/sm-hist.htm
I’m a little confused. I have a smith grandfather clock marked smith made in gr britain enfield clock co. It has weights and a wrought iron plaque that
reads GREAT BRITAIN GONG. The front plate reads tenfus fugit and
to the left it says silent chime. Did I misunderstand your description or is mine older? I HONESTLY AM TRYING TO EVALUATE IT AND IF YOU CAN PROVIDE ANY INPUT THIS WOULD BE TERRIFIC. THANK YOU SO MUCH.