610 I once played golf with a (I think it was nephew or similar) relative of Ian Fleming’s, at Frankston Golf Club.
I think he ( Ian that is) lived at one time in Barbados?
581 - is visibility the difference between fog and most?
589 - Angola
606 - Marlboro
573 I’ll guess Sam Goldwyn
606 I’ll guess Lucky Strike
613 FBI Federal Bureau of Investigation
614 Bill Cosby
615 - C-3PO
616 - Horse hair
599 shadows?
594 hangman, executioner
603 Blackbeard
600 canola
579 heads
Updated. Check answers in OP.
Ran out of likes in Olympics thread 
- Camels
1 Like
509 - not wear any underwear
614 - Bill Cosby
619 - tomato
612 A padlock?
619 Potatoes?
579 - heads
1 Like
I mean…right? It was specifically designed as a more humane method of capital punishment.
They used it in Nazi Germany, certainly for civil executions.
But in the TV series Babylon Berlin, set in the late 20s, a bloke did it with a special axe.
580 - France (they’re always at it)
I’m going to guess Israel.
(It says ‘had’ and in the Bible, Methuselah lived until 900 or something. 
)
1 Like
619 Beans
Lets go for some answers that would get a klaxon on QI:
509 he reused something, maybe string?
519 baby songbird
528 no idea what George Washington is reputed to have soaked wooden false teeth in , but i was thinking wood was an unusual material to use as real teeth and ivory had been used from much earlier, and checking the Wiki article on dentures to check if wood was ever a thing it is specifically stated that George Washington did not have wooden false teeth.
530 Joan Rivers
534 USA
546 witchcraft
552 cartoons- Mickey Mouse?
553 Japan
562 gold content
564 Denmark
573 Alfred Hitchcock
581 mist rises up from the ground, fog comes down from above
587 Coronation or jubilee of one of the Georgian kings
592 Bringing up Baby
600 turnip / swede
608 Guinea pig
616 hair / bristle
619 - Potatoes 
617 - Caviar