Ridge and others have made extremely overripe Zinfandels from back in
the 70s and even earlier. Some had a little residual sugar and a very
high alcohol content. Others had a very high residual sugar content and
high to very high alcohol content also. Some of the dryer types did have
much of the weight and structure of an Amarone. Some of the sweeter
versions had the weight and sweetness of port, or beyond. I suspect the
ones you mentioned were rather tame compared with some of the wines from
the past. Ridge Shenandoah Esola Vineyard 1978 was a fairly dry huge
late harvest wine somewhat in an Amarone style. Ridge Lodi Essence 1972
was very port-like with much residual sugar and alcohol. Ridge Dusi
Ranch Late Harvest 1978. was quite full and quite sweet. Monterey
Peninsula Winery Ferrero Ranch Late Harvest 1976 was extremely
concentrated, loaded with alcohol, and off-dry. Then there was David
Bruce who in the 70s was one of the kings of monster wines including
Zinfandel and even a Riesling fermented to about 17 % alcohol.

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