Monroe Gasket was the manufacturer of the Rochester Rifle. An example of which is currently up for auction.http://www.ebay.com/itm/Vintage-Rochest ... Swb3NZq0Mj

However, there is another Monroe Gasket and Mfg item up for auction.... a toy microscope.

http://www.ebay.com/itm/1940s-Vintage-C ... OSw-0xYdUK~

I think Monroe may have simply 'labelled' this product.The same way Pathescope did in England. I have one somewhere...in a Gilbert Science outfit.Trev

The history of Rochester tends to influence me on such a question. That history is that things are made there: small things, intricate but cheap parts; as part of the legacy of having the mighty Kodak there.

So, more likely than not, Monroe either made or assembled these microscopes from locally (Rochester) produced parts.

I would think for a serious Rochester/Kessler collector, if such a thing exists, that this little microscope would be a valued item, since it helps tell a story about a company that we know almost nothing about.