I believe the key cut is 67767 on a kw1.
I run across these alot.
mostly on properties that have gone back to the bank for whatever reason. Foreclosed, abandoned.
Fannie Mae had a key code they me re-key all there properties to. As well as Bank of America, Wells Fargo and so on.
Normally Enclosed in the Escrow agreement is the cost to have the newly purchased home to be Re-keyed from the bank master key to a Random key code.
Sounds like this didn't get done.
I know a ton of locksmith, vendors, cleaners, painters, house flippers, construction workers........on and on.
Have that key.
Re-key the house!
Check out
WWW.MFSsupply.com, any one can buy these keys. Or buy the lock and select which bank key you need.
Thanks