Clutch disengaged and stuck

Taking my first shot at getting a stored bike running.  I picked up a 1976 KZ400 that I was told had not been run since 1985.  Somebody obviously prepped this for storage as all the gas was drained (inside the tank looks like brand new), oil drained and brake fluid drained.  
The problem I'm having is that the clutch is stuck in a disengaged state, but nothing is holding the clutch lever in.  Is this something that someone might have done in anticipation of storing the bike?  Just wondering if it is something that would have been done on purpose (somehow) before digging in to find the problem.  
Thanks.

The free-play adjuster may have been screwed in to separate the plates so they don't stick together during storage. I would start by re-setting all the adjustments as per the workshop manual (free-play first, the cable adjustment)