Yes, I know several ways by which this safe can be opened but you don’t really expect me to enlighten you in public do you?
Consult a local MLA lock and safe man and ask for a price. When opened it will be repairable and new keys supplied.
As for expecting to get a key which will open it just by knowing the serial number is quite unrealistic when you consider that
when the first owner purchased it he would have paid about £20. Not much for the knowledge that you are the only person
with a key that will open it until you put a real value on the sole access which in today’s terms is equal to about £1,000.
Locked, your safe is worth nothing. The cost of having it opened will most likely be more than it’s worth.