Tach cable leak mistake

Ordered a new oil seal to fix my tach cable leak on my 78 kz650 and of course I forgot to order a new gasket (92065-103). Took everything apart and need the gasket to put everything back together. Won't see the part for another week. Can anyone offer any advice on an alternative? Or am I stuck? Also, the old seal is so rock hard I'm having trouble cleaning it out properly. Any advice on loosening up that old hard rubber?

go buy some gasket material at the auto place and trace and cut one?get a dental pick if you dont already have one from a hardware store 3$ and toss it in the box when youe done it'l grab stuff and pry and scrape too...

If the gasket you're referring to is the 1 at the Ferrell nut on the cable to the drive. I use an O-ring here. I've had good success no leaks. Since the cable must be lubed anyway if the drive seal is a minor leak, then a O-ring at the Ferrel nut when installing the cable will send a small amount of oil into the cable housing, lubing it instead of your cylinder head/ engine/ driveway.