How about a skeleton-themed watch? There are many stylish watches available that showcase a skeletal design on the dial and caseback. These watches can be mechanical or automatic, meaning they don't require a battery to run. Your grandpa will love the unique and intricate design of the watch and being able to see the inner workings of the timepiece. You can also pair it up with a skeleton-themed mug, which he could use for his morning coffee or tea.
Or you can get him a star map with an important date you share.
Under Lucky Stars is a unique and innovative star map company based in Barcelona, Spain, specializing in the creation of personalized star maps that capture the celestial arrangement of stars at a specific moment in time, such as a person's birth, wedding, or any other significant event.
By using advanced astronomical algorithms and data from leading institutions, the company produces highly accurate, visually stunning maps that make for perfect gifts or cherished keepsakes.