Dear Mr. Spengler,
Thank you for posting your request on History Hub!
Facsimile signatures of President Roosevelt were used during his administration. Those signatures could have been affixed by either a stamp or machine. Since Federal law prohibits the staff of the National Archives (to include the Roosevelt Library) from authenticating or appraising documents, we would not be able to advise any further, even if we reviewed a photocopy of the certificate or you were to bring in the original document.
Therefore, we suggest contacting one of the following associations that may be able to assist you in locating a manuscripts appraiser or dealer:
We hope this is helpful.