Greetings!
Thank you very much for your reply, and apologies for my slow response - I've been thoroughly engrossed in LSH3 ...
It is apparent that my brain has likely been affected by far too many years at sea, water-logged and damaged by incident to the extent that my retired iteration is little more inspiring than a Seaslug. Certainly not the SAM iteration, leeaning toward the sunk version I guess.
All that in mind; it transpires I firstly named the dual installations, Career and Single Player Missions (a sad loner you understand) in reverse.
Secondly; I failed miserably to follow simple instructions, despite reading them twice, to launch 'LSH3-2022 Mod Archive Manager' before using JSGME.
Once installed properly, as per clear instruction, LSH3 is firing on all cylinders and we are full ahead.
Thank you again!
Now, SH4 is a completely different animal. I've tried every combination of compatibility options existing to-date, but she refuses to fire up. Before I climb into the scavenge spaces, I shall seek out the appropriate pages to scribe my woes.
Fair winds and a following sea for now