This listing is for a Vintage 1967 Nupro Specialty Valves & Filters for Instrumentation & Research Concise Conversion Tables and Circular Slide Rule. It has never been used. Please see photos as they are part of the description.
The case is advertising for Cambridge Valve & Fitting Inc of Wayland, MA. It came from an estate in Fitchburg, MA. The owner was an engineer and had quite a collection.
You can see from the photos that everything is in amazing condition. The manual has never been used and the date inside is 1967. The case has a blue circle underneath the Nupro wording. I think it is from the grommet that is holding the Slide rule together.
This is an amazing piece of history to add to your collection. Thanks for looking. Email with questions. Offers welcome.