Unfortunately though there's nowhere in the config file that mentions
MSHOME in anyway shape or form so I've no idea as to why this PC
appears in the MSHOME workgroup and not the Workgroup which is set in
the config file.

Where do I find the GUI to run it once I've installed it?

I've found Samba in the >Sytem > Administration menu Is that what you
are referring to ? and yes in there it says CASTERBRIDGE which is the
Workgroup that I set it to.

I'd very much appreciate any help sorting this out as it makes no
sense to me at all.