We're renovating a Victorian terrace house. All the interior door furniture is painted over and doesn't work. Out of curiosity i've taken one apart, to see if it can be fixed, but all the interior bits (not that there are many, there doesn't even seem to have been a spring - is this normal) are worn. Is it worth while trying to source replacement parts? I'm reluctant to put on a different handle as all the holes will be in a different place, if you see what I mean.