Very used old watch from my grandfather. Trying to see what the value is and age to see worth repairing.
The date stamp on the caseback looks to be L6. If that is correct, then we can say the case date is 1956. Please confirm.
As for the model, it appears to be a Storm King. There are two variants 'A' or 'B', specific to the band it originally came with.

1957 Linebook 131
1956 Bulova Storm King looks to be a good match. As for value and whether it is worth fixing is entirely a personal thing. Very few non-luxury watches will be worth more than the cost of repair. That being said paying around $150 to have it serviced which is less than most new watches you will have an heirloom from your grandfather that is priceless.
1956 Bulova Storm King
1956 Bulova Storm King
Thanks for the help to identify this watch. Now to make a decision on whether to repair or not.