I have a couple of 7 speed LX rear hubs (560 and 563) with their original freehubs and I have two new HG41-7ac cassettes, neither cassette fits either freehub. There’s about 1mm of play between the 6 cog block and the small ring. I’ve tried a spacer at the back but the 2 rivets that (I’m guessing) hold the block together press onto it and skew the angle of the cassette. Are the modern HG41 cassettes not compatible with the old 7 speed freehubs? Or am I missing something?