I've got an air cleaner just like that on my 58 - 62 235. There is a small oval brass tag on the top - that has unfortunately been partially ground away by another owner - but if I fill in the blanks and read between the lines it indicates that the filter was manufactured by General Motors in Canada and should be returned to an authorised Pontiac dealer for service. This does line up with a small tag that I found on the carburetor which said Pontiac on it.