Okay, so I think I've got a bit more information after taking the boat out today. The wind was 11+ knots, my crew was really struggling to sheet or even hold the spinnaker. I've gotta get this sorted out. I had to rush once we got the boat out of the water today. But I'll get out to the club one day this week and take off one of the hull mounted blocks. If I can't get it to ratchet I'll take it to the rigging shop and see if they can advise. Otherwise I'll just replace it. I want to thank everyone for all their help, and I have realized that the existing setup is definitely not working.