I owned one of these, and donated it to the Reed Organ Society of America. This is a pump organ, also called a melodion or harmonium, depending on construction. Mine dated from the 1910-20s or there about. Looks like your Grampa the in the background. This had no resale value, but he would be happy to know that people who lovingly restore them would be glad to have it. Looks like mine - is it a Mason and Hamlin? BTW, I am donating all my late Dad's Naval Air things to the WW2 Museum in Louisiana. I have pics and memories - we want the real things to go somewhere special. Is Gramps a Vet? If you, thank him from me for his service. Last of the Greatest Generation.