Hi Eddie
The Somme is actually a small map made ,that I cut out of the center of the Western Front map
it can be done,but is a bit of a chore to do
not sure if I would have time to create an even smaller map of the Somme
maybe some time when I don't have so much on my plate
Object count only effects load time of the map,it does not effect fps
so as long as you can load the map in FMB,then it works for you
as for the length of time it takes to load,you just need to be patient
only the amount of objects in your view will effect fps
and the amount of different objects,the more objects there are,and or the more different objects there are... the harder it is on fps
You yourself could open Unlocked,and start deleting buildings in and around the city's
that would improve fps for you

delete whole citys and villages outside your flight zones to improve loading time

I'm not sure what you mean,by an older Pc
other than you do say"running it"
so I suggest unlocked and delete buildings so it still looks good for you,and plays better eventually for you
cracking the actors into a text file you could edit out huge amounts of objects editing them out in the text file
then compile a new actors.static
The actors management tool is extremely easy to use
and unlocked FMB is the same,easy to use
There is a lot of info out there on how to do anything in unlocked
so feel free to modify the map to your system
Sorry I don't have time to create another map for you
maybe someday I'll be able to take a look at this,but for now I am much to busy with what I have on the go at the moment
Cheers