jobpatto,
You're right, it was the Me163 that was rocket-powered using a hydrazine-based fuel.
I think the "Me162" in the early post was a simple typo, or an unintentional confusion with either the Me262 or the He162.
jodeliste,
The original design was indeed by Bristol Aero Engines, which then became Bristol Siddeley. But the latter was taken over by Rolls Royce in 1966, so by the time Concorde first flew, it already had become a Rolls Royce engine.
CJ