Okay I just looked at the vine and here it goes. There is one cane or arm I think it is and it goes from older wood to younger thinner wood it is in the pic of where it splits into a Y shape and the top one is the younger one that is producing grape clusters all along the cane. Now the older and thicker wood has a young cane growing out of it that is about five or six feet long and it has some grape clusters and down along the older vine I left two buds per node and they have a few clusters of grapes.
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Older with young cane coming out

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Older with Grape cluster
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Young cane with grape clusters
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Top one is the younger cane, the bottom one is the older cordon.

nice looking vine! I'm as clueless as you say you are about grapes, but, I know the old, fruiting canes don't re-fruit the following year. Heck if I know what the old canes look like, so, I just cut back a little of everything. This way, the new growth from last year will fruit. If you cut back the new growth from last year too much, nothing will fruit. If the canes are long enough from last year's growth, they will fruit. It might take another season for your young canes to bear fruit. Sorry if this is confusing. I just cut back a little every year and let it grow on and not worry too much. I'll let the "vintners" out in Calif. worry when they're making my wine. :-)