Sightmaster S-15
(click on picture for high resolution image)
(1947 - 15 inch)
This set has a chassis made by Transvision, a maker of kit sets. Sightmaster may have bought kits from Transvision, assembled them, and made the cabinet. Another possibility is that Sightmaster and Transvision were affiliated, with Sightmaster being the seller of fully assembled sets.