Guys: I start to look into semaster deville models from 50s and 60, and find them to kinda difficult to judge regarding if a watch is all original due to the many variations out there. thoughts on this topic? Just to list to a few I have seen: 1. curved caseback with engraved seamaster logo + 14k gold filled + simple indices/hour markers on the dial 2. curved caseback with engraved seamaster logo + 14k gold filled + simple indices and number markers at 3,6,9,and 12 on the dial. 3. bubble caseback with engraved seamaster logo+ 14k gold filled+ simple indices 4 bubble caseback with no logo+ 14k gold filled + simple indices 5. smooth and flat caseback with no engravings +14k gold+ simple indices on the dial 6. SS caseback with engraved seamster logo + gold cap bezel +simple indices any info on identifying the variations would be greatly appreciated!