spindle knobs

My house is old and every interior door has old glass doorknobs which are of the spindle and set screw type. They haven't worked right in the 20 years I've been here. Recently the bathroom doorknob broke. The latch doesn't come out fully and the door won't latch shut. It has a deadbolt lock under the knob but since the door is out of plumb (I have solid wood doors, the old style) I have to put my knee into the door to lock it while someone is in the shower. Every other door has a stripped set screw or knobs that just spin around. My question is, where can I buy a complete new spindle, knob and mortise lock set that will match the old glass knobs I have now. I've looked but can't seem to find them. The other question I have is would it be easier to just convert to the newer style doorknobs like I have on my exterior doors, the kind withough the spindle and setr screw set up. How hard would this be, what is involved and where could I find good decorative glass knobs (home expo?)? I know its a lot of questions but I appreciate any help you can give me. These knobs have to be at least 40 years old.

 

I'm not sure I have these sites exactly right, but I know they have what you are looking for. Try Vandykes.com or Vandykes Restoration Hardware on a search engine for new products. Try Oldhouseparts.com or Architectual salvage door knobs on a search engine for used products. I don't know enough about locks/knobs to say if you would be better off replacing w/new style. However, if you are after the period look, you can get that through Vandykes. I have used Vandykes catalog to get many things for our house, I also know there customer service is very helpful. Ask away, they will help you solve your problem. They have additional items not shown on web/or catalog. Make sure you ask them if they have what you need if it is not shown.