Do a search of this forum on Trillium
belly band repair. Known design flaw, well documented repair. The belly band repair should be completed prior to any exterior painting
Search via google, there are hundreds of documented repair discussions. Its one of the worst design flaws on the vintage Trilliums.
Randy Bishop and David Tilston are two forum members that have owned multiple vintage Trilliums and are well versed in the repair. I patterned my repair after their work: some Randy suggestions, some David.