I've got that very book somewhere,given to me when I was an apprentice in the early seventies by my old Dad,he like many guy's from the fifties & sixties dabbled with tv's & that new fangled stereo sound.When I was apprenticed,where I worked we had a AVO valve tester,looked like something from a Frankenstein film.Old boy's used to bring their valves in for testing,for a small fee.Trouble is they often washed/polished them up removing all the I.D. letters numbers.One of our engineers though,if they told him their set make model,he could tell them which valve was which & its type(proper old engineer)He'd be bored by our throw away panels we have now. Lol. I remember him well,I think Rank introduced the first t.v. with an i.c. fitted,which died if the EHT flashed over,he pronounced them "Bloody rubbish"Transistors"Bloody rubbish,fiddly little*******"followed by won't last five minutes.I just remember when it was quiet o.k. to fix a mains droppers with a RS dropper section.Although I did a Philips G8 once o/c section,like a fool,didn't discharge the main smoother,I can still feel the belt to this day,lesson learnt.