I am not sure that "there must be one somewhere". Photographs were very much a luxury. There must be hundreds of people from that era for whom there never was any photo. But, assuming there was, then the most likely people to have it would be family, and you say you have already contacted rellies. I am not sure who else would be holding a photo, and know who it was of! But I hope I am wrong and you find what you are looking for.