1922 Essex Clutch Issue

Took the SX out the other day to get a better feel for the clutch issues and this is what I have come up with. This has the multi plate wet clutch. It seems to be adjusted about right in that the peddle is the correct height from the floor. However the clutch slips badly. No matter how fast or slow you let it out it slips, then eventually it starts to grab when the engine and trans start to match speed. There is no chattering or other strange noises or jerks. It is just smooth (a little too smooth). At a start it just sits there then starts moving slowly almost no matter what the engine speed it. To me is seems as though the corks are coated with something. If this were a dry clutch I would say the springs are weak.

Any thoughts would be helpful. I have not drained the fluid yet but a good flush may also improve things. What is the best way to flush this beast? or what other things should I check? Also in the event it needs to be rebuilt, who could handle such a job?

Thanks, Jay