I had the mechanical lock on my safe replaced with an electronic one after the tumblers siezed. Luckily, they siezed with the door open.
The electronic locks are much better, and just as secure.
Be prepared to hear how thieves will "blow" your electronic lock with 110 volts ac. This is just as likely as them starting your car with 110 volts ac.
I have a 6 digit combo on my lock, which I can type in, in about a second. With a four digit dial type combo, you will be there quite a while - and don't even try it in the dark, or under ANY kind of pressure!!
In case the internal battery in my safe runs down, there are two external electrodes that you can attach a 9V battery to. The circuitry remembers the most recent passcode, and does NOT revert to a factory setting such as 123456 etc.
For me it was worth the extra $140 it cost - a rip off, I know, but what can you do?
Bowser.