Two questions. . . Have two--I think--matching filters: a 526 9606 010 and a 526 9605 010, Believe both are 2.4 KHz bandwidth and think one is upper and one lower SSB. Anyone know what Collins unit they fit? How difficult is it to find a F 455 Q 5 filter for the 75S-1? Anyone have one and what price? Thanks Buck W0LC