if you have both bikes available, yes. But if you're sitting at work / at the in-laws for Christmas dinner / on the loo / in the church / wherever, not so much.
I've got the EFE speedo working correctly on a Slingy wheel and speedo drive. But the Katana has a 19" wheel, so if the drive is also different from an EFE or a Slingy one (different reduction) it might work.