you may have a fluid lock so I woul say to open the bleeder a bit and with someone to help push in the clutch and then close the bleeder. Not sure why it would lock as the whole system is pretty flismsy. the master is almost all plastic in construction. Did you check under the dash to see if it became disconnected? If it sat for 7 years I would recomend that you first R&R the master as the slave is a PIA the trans has to be pulled to access. The master is no fun either but I would at least start there.

One thing there could be trash in the line and it is clogged so try to flush by opening the bleeder as I first suggested. Make sure you do not let the clutch uop if it goes down with the bleeder open as it will suck air. Bleed close and then let up on the clutch.

There should not be much more to check as it is a simple system.

lots luck