The only thing that comes to mind vis a vis Cuban records is to contact the Patronato in Havana for further guidance:
Synagoga Beth Shalom
Calle I Esq. 13, Vedado, Ciudad de la Habana, CP 10400, Cuba.
Tel: (537) 832 8953, Fax: (537) 33 3778
E-mail: beth_shalom@... or
patronato_ort@...

I believe the main contact person would be Adela Dworin, but I cannot guarantee the currency of the contact person.

I hope you can locate the Cuban archives holding such documents, because there  are many descendants of Cuban-Ashkenazim in the USA who would be interested.

--
Adam Cherson, NY, NY
Benyakonski, Kherszon, Rubinovich, Solts, Grodsinski, Levine, Cohen, Kaplan, Lubetski, Karchmer, Horwitz, Rabinovich, Zussman (Lida, Voronova, Dieveniskes, Konvaliski, Smarhon, Vilna)
Genomics Publications and Presentations: https://independent.academia.edu/AdamCherson