1960s vintage 9" GE B & W Portable TV has no Picture

[Captainclock]

Hello Everyone today I had received from a friend of mine from church a 1960s vintage General Electric 9" Portable Black and White Television Set that when I got it home to test it out I got perfect audio but no picture, and from what I could see through the vent holes on the side of the unit most of the tubes that were visible through the vents were glowing like they were supposed to be, and from what I saw online on some YouTube videos about vintage television repair that if the video amp or the vertical or horizontal amp tubes are blown there isn't going to be a picture so I wonder if it might be a bad video amp tube or a bad vertical or horizontal amp tube inside the TV, or could the TV tube perhaps be blown? Although I thought that if a picture tube blew that there would be black sooty looking spots on the inside of the screen which there aren't any to be seen on the screen.

Any suggestions as to go about restoring this wonderful piece of history?

Pics are coming later when I have access to my camera.