AR XB headshell/tonearm

I have a good condition AR XB that I am refurbing and am having trouble with the headshell.  The carts that I have either don't fit the headshell or fit poorly such that they aren't alignable.  Is there a reasonable replacement headshell or am I going to have to replace the whole tonearm?  I'd prefer to not drop the coin for a whole tonearm but on the other hand this is a back burner project so I'm not opposed to sitting on it till I put aside a little money for a tonearm if that's how it's gotta be.
thank you