Boucher birds on nest?

Do you think this this a legitimate early Marcel Boucher brooch? This item is from my mother's estate of costume jewelry. The brooch measures approx 2 inches by 1.5 inches. I haven't been able to spot an exact photo of this brooch online. The upper portion almost exactly matches a 1940 brooch love birds on a branch. Lower left of reverse side appears to have a hard to read "MB" mark.

Please let me know your opinion.