Here's my 1968 RCA 19" color portable that I purchased at an estate sale about 8 years ago, It even has the original stand, Although not shown in picture. Took a while to find this model, The last one I saw was when I owned a tv shop back in 1981!
Seems that heat related failure, I.E. caps, Tubes, P. C. boards and tube sockets (becoming brittle from heat)were a problem with these models. I saw the most come in when I was working for a shop in the mid to late seventies. Most were done by then, As I remember replacing a 6GH8 in one and having the socket crumble, When trying to replace that the pc board itself began to give way! It was a loaner we used for our customers so rather than have more problems, We tossed it into the dumpster!
This set in the picture had only been serviced by RCA under their service contract which ended in 1980. The elderly lady that I got it from stopped using it in 1981 due to a dirty tuner. So if she hadn't decided to put it in the basement, It would have been in the landfill years ago!