I am not sure who made them, it could have been several factories ....lorez would know for sure.
Thanks for the vote of confidence. The USA Swift company had its home office in Boston and the microscope warehouse was in San Jose, CA. The company started importing binoculars, telescopes, and consumer optics such as opera glasses. Microscopes came along after the WW2, as best I remember. The earliest serial number I remember seeing was 1957... a good year for Chevy and Swift. The serial number on the scopes imported by the original company always had the year of mfg. as the first two digits of the serial number. Letters identified factories which were all over Asia. Swift actually specified the designs of the scopes they imported. This is no longer the case with current importers.
The USA Swift brand was targeted at the educational market with a couple of models that were for the veterinary market. They had no desire to do anything else... I know, I asked, but they did what they did better than anyone else who was serving the educational market. They offered a lifetime warranty and stood behind it. There were parts in the warehouse for every model they ever had.
The microscopes were sturdy, well built (for the price point) and because there was amazing support they would last forever. They never claimed to be anything but what they were.
APO is right about the current Swift line. It is made in China and is probably no better than anything else, but the support is gone. The current reps have no idea of the history of the name and know nothing of the models that existed before the sale of the company. I no longer have any affiliation with the brand, but still work on all the old stuff. This in no longer as easy as it was because there are no parts.