Back in the day, these were the only game in town if you wanted to display an image on a 40' diagonal screen. I worked for an AV production company which rented these out to tradeshows, shareholder meetings and large stadium type events like rock concerts. I believe the Rolling Stones owned a pair.
Eventually, the projectors needed replacement light valves, which at a cost of nearly $30,000 apiece, made owning them cost prohibitive. We replaced the GE Talarias with Barco Light Cannons which were brighter, used more conventional light sources, only needed 110v power and could be moved without the aid of a forklift truck. Also new Barcos were cheaper than the cost of the replacement lightvalves.
Even though we paid over $100K for the GEs when they were new, we couldn't find anyone adventurous enough to sell our old ones to. I understand, these units are currently being used as boat anchors.
Good luck to you, if end up buying one of these monstrosities. Make sure to ask the seller if a forklift is included in the selling price.
Richard