A little over a year ago, a group of us did a Gran Reserva tasting/dinner. Tondonia, Bosconia, and Blanco. Notes are here: TN: Lopez de Heredia Gran Reserva tasting, 1947-2010
I just purchased a bottle of '54 Tondonia Reserva from a friend who is a major Rioja collector. Birth year wine for me. He also sold me a bottle each of '54 CVNE Imperial Gran Reserva and '54 CVNE Viña Real Reserva Especial. That friend goes to Europe to source wines and sells them to friends for the price he paid. He’s not ITB.
FYI, he told me that LdH didn’t start labeling their wines as Gran Reserva until later. I can’t recall which vintage. Although wines previous were labeled as Reserva, the élevage was the same as GR. I might be seeing him today at a winery pickup event. If I do, I’ll ask about when Heredia started R and GR differentiation.