My experience with public model train displays is that there is an initial curiosity but the repetitive nature of it's running soon looses it's retaining attention and it then becomes easily ignored.
There have been several merchants and hospitals in the area with trains over the years but they failed to have a lasting presence.
The only way model trains seem to have staying power in a retail environment from my experience is when they are big G gauge, ceiling hung and not diminishing retail floor space or a limited time holiday activity. To a business, floor space really needs to yield income. Generally speaking hospitals are a big business.
We have an interest in layouts because there are so many facets of personal expression in which we find satisfaction. To me if someone is not personally involved in the development of a layout there can be a "so what" response.
MTH really raised the bar when they promoted electronic interaction, but that star is fading away.
When I look at the state of model railroading business I ask myself "Where were all the bidders standing in line to buy the business' of Jerry Williams, K-line, Joe Hayter, Mike Wolf, etc, etc," The only way one can make a million bucks with trains today is to start with two million bucks.
As far as selling the double helix, consider approaching a 3 rail train store which may have available space, maybe a store window. The transaction IMO needs to either encourage sales or offset the planned expenditure of money. You are looking for jumping into the path of a cash flow.
I have sold several demo layout displays over the years and I wound up selling them to folks who lingered at train shows. They wanted to get into trains and my display got them started instantly. I simply was in the path of an impending cash flow. IME
