The Solana was not an open framed tandem, but a double diamond framed tandem built in 1983.
Listed by Santana as a 'mid-priced' tandem but without hand detailing and without some of the more expensive components on their other twicers.
At that time we had a financial stake in a local bike shop that handled Santana and also Dawes (English), Gottfried (French) and Berry (local custom) tandems.
Santana's built some very lmited production bikes including the Moda.
They will, build almost anything custom, including a single speed multi-seater for the Disney folks.
Exogrid is just an upscale/pricier/fancier version of Isogrid in our estimation.
Pedal on TWOgether!
Rudy and Kay/zonatandem