Update:
I've binned all of the boards.
I'm not happy with how they were going - particularly the water effects on the river sections. In retrospect I think that smaller boards would have made more sense - I used 600mm x 600mm baseboards for the Nam project whereas my latest project (Planet of the Apes) is based upon 450mm x 450mm ones making them easier to store and transport.
Rather than try to rescue the Nam boards, I'll come back to this project at a later date, and start afresh having learnt from my mistakes.
Space wise I can fit 3 projects under my tables, with another obviously on top - currently I've got the Battlefield and WW1 Fantasy boards (both finished) under my table plus the Galactica Project (WIP) so anything else has to be spot on otherwise it gets binned.
For now i'll turn instead to the Planet of the Apes project, before I move the Galactica project on a bit more.
The King is Dead, Long Live the King!