h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Interesting to note that, Sondheim's musical aside, the story has been told as a true crime story since it was first documented.

And strange to note, in an early (1936) Black & White talkie, Fred Hayward version, the part of Sweeney Todd was actually played by and actor named Tod (Norman Carter) Slaughter! (Tod was apparently a stage name, but the Slaughter was real?!?!)

I do remember seeing a telly special on the Fleet Street murders. I can't swear that they actually "proved" it all, but it seems to me that they claimed to have a comprehensive list of the victims, Todd's spoils, and even located the shop and barber chair mechanism. Some of it could have been a reconstruction, of course.

I'm sorry to even bring this up when I can't be more specific.

I'll look into it a bit further and, if I find anything that appears helpful, I'll be glad to come back with it.

The closest I've found is this:
http://monsterkidclassichorrorforum.yuku.com/topic/1117
[But about the true origins of the story, sources conflict. Some of them mention an old French criminal case as the real source of the Sweeney Todd legend. In the 1770s, a barber had his shop rue des Marmousets, in the Gobelins quarter of Paris. He killed many of his rich customers and his accomplice, a baker, made delicious "pâtés de viande" from the corpses and became so renamed that even the King's Court served them at Louis XV's table !
Legend or reality, I don't know.]

Me either!

I found a site that admits to the urban legend flavour of the Fleet Street barber. It also cites a book which may have been the basis for the tv special I remember:

http://www.crimelibrary.com/serial_killers/weird/todd/bogeyman_1.html
[There really was a mad barber, he really did use a trapdoor and straight razor to rob and kill customers, and most did end up as filling for meat pies. Extensive, painstaking research by British author Peter Haining has shown this without a doubt.]

Good luck with the piece,