A bit of a longshot I know, but can anyone help with a title of a film
I saw many years ago....all I can remember about it was that it may
have been set in France-I recall a guillotine scene. Also there was a
scene in which mannequins were being put into a furnace and these were
mistaken for human bodies.....despite this I think it was a
comedy!!...May have been made in 1960's....

Hello simonfen

The only one I can think of is:

"Carry On...Don't lose your Head" 1966

"Paris, 1789 and the Great Revolution is underway. The noblest heads
in the land are being lost to the fearful embrace of Madame
Guillotine.

Sir Rodney Ffing (Sid James), an Englishman of the finest breeding,
decides to lift a little finger (or even two). Daring rescues are
staged and a calling card is always left bearing the contemptuous sign
of that damned elusive The Black Fingernail.

Searching for Ffing and his faithful partner, Lord Darcy, are the
fiendish Citizen Camembert and Citizen Bidet.

Will the Fingernail's true identity be discovered? Will Camembert and
Bidet have the last laugh? Will you manage to stop laughing your head
off in this hilarious romp with the best of the Cary On team?"
http://www.carryonline.com/carry/cohead.html

Could this be the one?

Regards

THX1138