I'm not aware of Cadillac having any sort of unusual fittings on its brake lines. Do you know what year the rear end is from?

Brake hoses and lines are all readily available from just about any source such as OPGI, USA Parts, etc. InlineTube supplies pre-bent brake lines with the correct fittings.

I'll see if I can find out exactly what fitting is used.

1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)