I found out some more-- PowerMax gens have DUCAR engines. That led to this website, which shows their line of inverter-gens, which includes that 2500w one that was mentioned for Westinghouse.
http://www.ducar.cn/productMechanies/18/The "about us" says they make things for several brands and their factory is in China.
More info. Pulsar "makes" them for about 10 different brands including PowerMax. Some are labelled "Ford", which is where that confusion came from:
https://www.amazon.com/Ford-FG2200iS-Silent-Inverter-Generator/dp/B075F8KJH9Pulsar has its own brand on some of the DUCAR related gens. Can't find where Pulsar and DUCAR connect that makes it seem like Pulsar is where they come from if you are a Brand.
http://pulsar-products.com/our-products/generators/