By way of contrast I have just restored this:
...a 1971 model 722 GPO Trimphone! I bought it looking rather grubby and tired looking for peanuts, stripped it down, replaced the cables and mic, gave it a damn good clean and plastic polish and it looks great and works a treat! Reminds me of the phone from when I was a kid at my parents. Much to my surprise it rings out fine here, not that I'll use it for that as I've a modern cordless phone. The iconic 'bleeping' ring is present and correct!
PS I've got an allegedly mint 300 series Bakelite phone on the way too as I've always wanted one and thought I'd treat myself.