I think I'd say that the Limeliters improved when Glenn Yarbrough went elsewhere - it allowed Lou Gottlieb and Hassilev to show they were the brains behind the operation. My favorite replacement tenor for the group was Red Grammer, but Rick Dougherty is a close second.
I went to some wonderful Limeliters concerts in the 1990's (and to one really pathetic Glenn Yarbrough concert). The Kingston Trio concerts I attended in the 1990's were a disappointment - to me, the Kingston Trio is long dead. But now that Lou Gottlieb is gone, I don't know how the Limeliters can go on, either.
-Joe Offer-