This is the HIPPOCAMPUS Steel Case Back which fits the Speedmaster range from latest 145.022 back to the 1960's watches 105.012 145.012 etc.
These are Omega supplied service case backs which fit the 42mm Manual Wind Moon Watch case reference 145.012. These service case backs have extra zero 145.0012.
This was fitted to the model stated above but will fit all the other case references for the 42mm Speedmaster Manual Wind Moon Watch models back to the mid 1960's once they introduced the crown guard Speedy.
112st1450012 Omega Speedmaster HIPPOCAMPUS Case Back Moon Watch 1963-69
Items can only be returned if either faulty, in the case of the item not being required then it must be returned exactly as received. For example if the item is new in a sealed packet and/or has protective covers in place then it must be returned the same otherwise item is no longer new and the value is greatly reduced, these items can only be returned/refunded by agreeing a lower value with Swiss Limited Editions before returning reflecting the new lower value of the item.