[Nick-Ko-Las Enigma]

http://www.victorianlondon.org/mysteries/sweeney_todd-01.htm
the original 1846/47 penny dreadful featuring SWEENEY TODD
THE DEMON BARBER OF FLEET STREET

[YouGotsToLovett]

I read that, it was different from the musical. Still, it's a very nice read.

[Sweeney Hyde]

I read it a while ago as well.
It is in bookstores as well.

[Vice]

I have a script version of that. >> Don't like it as much as the musical though.