I Did
Larry,I did just this about 5 years ago. My H376 is 1996 so it was about 5 years old at the time.The Philips head screws were seized too. I used lots of WD40 and after waiting some time, using a considerable amount of force, including one of those percussion tools, they came out. It was a nerve wracking time as I did not want to damage the deck nor ruin the screw heads.I guess if I had ruined the screws the option still existed to drill them all out, remove the organiser and grip the studs with a mole wrench. In the event it didn't come to that.I was replacing the existing sheaves with roller bearing types for the main halyard.More recently I did a test on my main halyard by hanging the Admiral on a bosun's chair and lifting her just off the deck with the halyard winch. Then I tied a spring balance on to the winch handle and pulled. It took 20 lbs to move her. So I took the halyard completely out of both organisers and ran it from the mast heel, over the coach roof and direct to the rope clutch. Repeating the test it now required only 10 lbs to raise her. ie. 50% of the winch power is lost in the organisers. Since then I have re-run the main sheet as well. In my case I have a tubular stainless steel guard for the dorade vents so I have put a small sheave on this to divert the ropes away from the dorades. It only puts a very small kink into the line so I doubt it affects the friction very much.For mote details see "Today I Hung the Admiral - (H 376 Main Halyard)" in the archives.Good luck.