We need stuff like that here in the UK! Unfortunately, shopping centres with organs are hard to come by...
And only the one store in the USA that I know about... Temporary "kiosk" style retail sellers, usually "seasonally adjusted"
temporarily make appearances in such facilities. "Enterprising" purveyors of redundant instruments could make use of this available space to temporarily install such instruments for the enjoyment of all,
the acoustic environment of the typical shopping mall I would think would lend itself well to such installations, plus make it much easier for prospective buyers or "rehousers" to evaluate the instruments in question