50's Sylvania Technical manual+futuristic letter

1950s Slyvania Technical Manual Sylvania Radio tubes.. It has some wear with some pages being loose. Inside ths book, marked June 1958, there is a letter application, & newsletter to the person RCA advertising their course along with ' A glimpse in the future' with some very interesting predictions of future technology which were supposed to be available by the 70s, do not believe all these inventions were made by that time but much later. Still, very interesting piecd of advertising.