Hi all, and thanks to Rob for the invite to crash your forum. I really only post at the TAG Heuer forum, so before reading what I say below, please understand that Bremont are far from being my area of expertise!
The Valjoux 7750 is an integrated Chronograph launched in 1974. Its used by many, many watch brands, including TAG Heuer (TAG call it a Calibre 16) and IWC....am sure you guys already know this.
In this case, the Soprod module is effectively a plate that sits on top of the base 7750 with the main (sole?) purpose being to modify the dial lay-out- the traditional 7750 layout has three registers at 12, 6 and 9 o'clock. To get the 3 and 9 o'clock layout you need a module on top of the base 7750 movement...but I wouldn't say this makes it a "modular" chronograph (that term typically being for a watch base engine with a Chronograph module piggy-backed).
Here is an example of the various 7750- variations that Soprod produce: Chrono sur base 7750
I also wouldn't say this was a Soprod movement...its a Valjoux/ ETA 7750 movement modified by Soprod.
you can see that the first one is very similar to the Bremont movement, except for the position of the date....which I agree is best at 6 o'clock.
And yes, Rob, I imagine that all those extra 3 jewels are doing is altering the layout on the dial.