Early 60's possibly a 24 or 27" tube?
Magnavox usually has numbers stamped on the individual chassis, usually on the rear apron, you'll probably have to look up the schematic based on that number since they used the same chassis in many different models.
Sams website has an index where you can look up the folder needed.
Once you know the number I would recommend buying one from eBay or someone here rather than pay full price from Sams for a PDF.
https://www.samswebsite.com/