1983 kz550ctd tach

Ok so I'm new to the site and as I'm currently knee deep in the first of two kz's I just bought (1983 kz550c ltd and a 1981 kz1000 csr) I need some help. The tach isn't working and upon inspection the cable is broken, no problem right just get a new one so I thought. The cable goes into the worm gear connected via a sealed sleeve, only problem I'm having is that I can't get the cable out of the gear, almost seems to be made as one but I'm almost certain that isn't correct. I've found several cables but none have the gear connected. I suspect I just need to fine another gear as the one I have must have just molded itself to the cable. Just wondering if I'm correct on the cable and gear being separate or if I'm completely wrong. I've repaired a lot on this bike while keeping it about 98% original and want to keep it that way. Any help would be appreciated. Also I'm needing an original air box for the kz1000 if anyone knows where. I'll get pics up in the morning sometime.

listing ended

Ya I let it sit in kroil for about a day and a half and it won't come apart. Looks like when the cable started breaking it twisted inside the work gear and at this point is fused in place. I found the gear on Z1's site and ordered it (hopefully the correct one) malsohavennew tach and speedo cables coming. Now just wait for tank to get back from paint and the bike is complete. And as far as the 1000 car I believe I'm just going to run a quad filter setup for the time. It need attention in several other places.