door locks

hi again. I have a dozen of old doors with very old door knobs/locks. I do not have keys. Also as you can see from the pictire, previous owners put fugly deadbolts in some of the doors.
So I want to remove deadbolts and to use original keys.
About deadbolts: what are the good ways to repair the hole from the lock? So far I tried to cut rounds plugs with holesaw but it is hard to find holesaw with close matching diameter. Even then the circle is quite noticeable.

about the keys. I took apart one lock and it looks very simple. Do you think I can buy replacement keys for this?

thanks

By bobjohn |