You are one lucky fella! Not only from within your family, making them heirlooms with history, but with just cursory looks they look like they will be excellent shavers. Looks like a mix of American and German steel, both give good shaves. They should be put in the hands of a professional honer to make sure they are shave ready. Valuations are not given on the threads. The real value lies in being family owned and passed down. You have no idea how many SRP members would like to be related to your Grandfather with his generosity. Have them honed and use them in health and happiness.