I've had Reubens (a favorite of mine) at many restaurants, Cubanos at many Cuban-style restaurants, and the Especial which wasn't Cuban-style but just plain Cuban, at Sloppy Joe's Bar and Restaurant in pre-Castro Havana. I copied it and it's been a family favorite ever since.
The Especial is a Dagwood-size production with many layers of cold cuts of five or six varities, interspersed with slices of different cheeses and mayo and mustard on wide slices of wonderful Cuban rye bread. The whole thing was six inches high and nine inches wide and a good 2-1/2 inches thick. I always headed straight for Sloppy Joe's for an Especial whenever my ship spent a few days in Havana for liberty.
You could get into more trouble in Havana, in those days, for less money than anywhere else I ever visited in the Navy.
Sorry for the digression.
So what, exactly, is a Cuban Reuben, please?
Someday I'll tell you about hoisting a couple frozen daiquiris with Ernie Hemingway as he held court at the left end of the bar in the Floridita restaurant . Those were the days!