I'm curious about the descriptive aspect of the layouts for the open-house and if you couldn't improve a turnout in the future with some spoilers focused on things the layout does have in common with another gauge's style.
For instance a picture/mention of older steam or small diesels switching may have helped; a log load or two; etc.. and though it's not your normal style of running, nothing really stopping you from running a normal consist at the same time 
I.e., cater to the crowds known interests and let the wow factor do the rest.
Is size even mentioned? 60 scale mile run on a 6 scale mile layout is pretty impressive even in HO or N.
In the end it's like a concert; You should get them there with what they "want". Then you can also show them what they "need" 
I've got a plantar wart that looks worse than that, if it makes you feel any better 
Some days it tempts me to pull a "Bruce Cambell" before it "swallows my sole"
