Thanks Mike ( or is it mikE?) but it is a wide-ish SSB filter that I seek. The CFS455J is 3.0kHz at -6dB and 9kHz at -80dB according to the Murata data sheet I have. The CFK455J from JAB is pretty similar (9kHz at -70dB) so may be the closest I am going to get.
The CFK*** are 11 element types and the CFS*** are 15 element types, so achieve slightly steeper sides but I doubt whether the difference is significant in practice.
Thanks & best 73, Phil.