Well, some time has definitely past and I've been remiss at not posting an update so here goes ...
At the right, the top portion of the removable mountain can be seen, covered with a plaster cloth and colorized just a bit to take down the whiteness. Note that a clear separation can be seen between the upper and lower halves, at this point I'm thinking of adding some additional plaster cloth seams to reduce the gap to something easily disguise-able ... I hope!
Taking at least a portion of the layout one step further and in anticipation of our first public showing, I've started the landscaping of a section of the mainlines. All of the ground materials and ballast are Woodland Scenics and mostly applied using Scenic Cement applied via dropper. The trees shown here were acquired via eBay from Architrees, my plan to heavily use pines although so far I've only scattered a few poplars and aspens.
Although a bit difficult to see in this picture, I've also scattered some weeds down between the two mainlines using grasses and a bit of scrubs ... I like this effect and plan to add more here and especially along the mainlines on the other side of the module.
Here is a view of the other mountain top also basically complete including the plaster cloth colorized finish.
So, at this point the module went off to its first public showing as part of a local train swap as seen below. Functionally, the module performed excellently with trains running quite smoothly throughout the day long event. Hooray!