Dick Ayers Fantastic Four 28 Cover Recreation

I believe this piece was commissioned by Christie's for their Art of Marvel auction in 1995. It measures 13"x19" and is signed by Dick Ayers in the bottom left corner. An embossed stamp in the bottom right corner reads, "Original Production Cel and Background Art" with the Marvel logo in the center.

I saw similar pieces where Dick collaborated with his son on other FF recreations for Sotheby's, but those pieces were not embossed, and they were signed by Dick's son in the bottom right corner. The Christie's item listing says that the piece was a collaboration with Stan Goldberg on colors, but Stan's signature is not on the piece.