If your looking for that old time look, restoration hardware may be just what your looking for. You can find restoration hardware readily available online or at local specialty hardware stores that carry a large selection of door hardware and cabinet knobs and pulls. You can find restoration hardware in all price ranges such as a solid brass mortise door hardware set that was custom made for a door which is about 31/2 inches thick. It came at a price of $1200 so you know I took great care in installing it.
You can get restoration hardware for any time period. Victorian, early Colonial, art deco, etc., are all available in different finishes. To preserve the authenticity of the door you will want to keep the doorknob locksets that sport full-mortise lock and latch mechanisms. These traditional mortise lock sets require a large, deep cavity in the edge of the door that holds the box shaped door mechanism. A bar is then inserted through the door and holds the door knobs. Today's door knob sets are tubular and requires a large diameter hole cut through the face of the door for the knob set and a smaller hole through the side of the door for the closing mechanism.
