A couple of Spitfire questions

["M. E. Foster" <foster_m@swbell.net>]

I just got a '76 Spitfire 1500 and I have two questions.

1. What oil filter should I use?

2. A book I have says that the Spitfire 1500 uses a ZS CD4 carburetor,
   but Victoria British only seems to offer parts and tuneup kits
   for the CD 150. Are they interchangeable? Mine has a manual choke.

Thanks.