Yes — this is the FDR Social Security Act signing photograph that belongs with the 1985 James Roosevelt mailing you showed.

The image depicts President Franklin D. Roosevelt signing the Social Security Act on August 14, 1935. Your accompanying letter specifically says that James Roosevelt enclosed a photograph of his father signing the Act, so the photo and letter have clear contextual provenance together.

For eBay, I would not sell this photo separately. The complete grouping is considerably more interesting:

Suggested eBay title:

1985 James Roosevelt FDR Social Security Act 50th Anniversary Letter Photo Lot

Price: I'd start at $39.99 Buy It Now + Best Offer for the complete package. If all of the original mailing pieces are present, I'd test $49.99 first.

Description:

Vintage 1985 National Committee to Preserve Social Security and Medicare correspondence from James Roosevelt, son of President Franklin D. Roosevelt. Issued in connection with the 50th anniversary of the Social Security Act and 20th anniversary of Medicare.

Includes the multi-page June 6, 1985 James Roosevelt letter addressed to committee member Gladys Felske and an accompanying black-and-white reproduction photograph depicting President Franklin D. Roosevelt signing the Social Security Act in 1935.

Original vintage political/social-history ephemera from 1985. James Roosevelt signature on the correspondence appears to be a printed/facsimile signature and is not being represented as an original autograph.

Pre-owned vintage condition with age/storage wear. Please review all photos carefully for exact condition and contents. Sold as pictured.