Power steering pump (UK)

["P.J. Nott" <P.J.Nott@newcastle.ac.uk>]

The power steering pump on my Audi 100 1.8 (4 cyl) '85 has developed a 
serious leak after remains of the fan belt became entangled around it. 
I found a good looking replacement off a 5 cyl engine but noticed that 
they are slightly different. The pumps are identical apart from the two 
halves are aligned differently, with mine having a green tag and the 
other a red tag. My pump is found at the bottom of the engine next the 
crank pulley. 
As I am going to continue my search around various breakers yards, are the 
coloured part number tags the correct way of differentiating the two 
types of pump? 

Thanks in advance

Paul Nott  p.j.nott@ncl.ac.uk
Newcastle Upon Tyne UK.