In my search for Sumner-8 info I also came across a six page thread somewhere with info on the Islands 15 and 19. There are references to places where replacement parts can be found and several people reported on sailing them. It seems I cannot post links here, but I'll do my best to point you in the right direction.
w w w . v o i l e . o r g /forumvav32/read.php?2,1063,page=1
Again, take out the spaces. I have no ties to either "link" and only offer them to help folks who are looking for info.
I tried to PM Truewind to tip him off that I can help him with his Sumner-8, but I cannot PM either. If someone can nudge him over here I can arrange a direct exchange of photos with him. I tried to get my post count up to where I cam PM and post links, but that disappeared. I am trying to offer help but the board is uncooperative. I'll go away if I'm not welcome here.