Call Hartwig in St. Louis. They will either have it or know where to get it. Those machines are rocks; we bought ours used in 1992 and have run it hard since. Not the fastest machine in the shop, but the most trouble-free.
I assume this must hold the pulley on? Why can't you just smack it to break the taper. I have never had much luck with just pressure to break a taper or compression bushing. You need pressure and a good steel on steel smack.
If this is the X axis and I assume the LB is a slant bed make sure you have a 4X4 blocking it up. Saw a guy use a C clamp on the way once ... didn't work.