[TenTec] Confusion re Inrad filters

[tlogan7 at cox.net]

Hi folks -
Inrad has the following filters listed:
#750 CW 400Hz 6299.25 center freq
#751 CW 250Hz 6299.25 center freq
#753 CW 400Hz 9000.6 center freq
#759 CW 400Hz 9000.7 center freq
#760 CW 250Hz 9000.7 center freq
  All are listed as suitable for Omni V and VI rigs. Which four filters
would be used on an Omni VI setup for cw with a 400 in N-1 and a 250 in N-2?
  I also understand that there is some type if adjustment that has to be
made to the Omni regarding center freq if you pop in these Inrads - is that
correct? Or does it only apply to the 2.8 SSB filters? I don't really
understand these things very well. Can someone clarify for me - I actually
asked once before but was a bit embarassed to admit that I still was not
sure about the center freq business. Thanks for any help.
Regards, Tim NZ7C