I just came into ownership of two of Granstaff prints. The first is from the Memento Series Plate 24 Sugar Plum, signed in pencil. The second is from the Memento Series Plate 11 Pla' Like, signed in pencil along with a written sentiment and the date 12-9-77. Both are in Mint Condition, custom framed under glass.Plate number 11 is sold out with no more remaining. I would like to know the value of these for insurance purposes. Thank you.