In our lamp shop we try to make the best repairs with the best parts, period. We do not want a customer to leave the shop with a lamp fixture that has problems or potential for problems. Sometimes we compromise on the type of part to use. More often we compromise on the style. We will never compromise on the safety of a lamp, so there are times when we have to tell a customer "sorry, your lamp cannot be repaired"
If you are a DIY lamp person or a small time picker it is important to know when is the right time to say: Put some jam on it, this lamp is toast. You need to make that decision at the flea market or in the Goodwill store and not in the home shop.
Here is an example. A customer brought in this lamp the other day and it was obviously broken. This is not the common flickering bulb or bad switch, this is a break in the body of the lamp.
It doesn't look like a bad break and probably only makes the lamp a little wobbly. A close inspection shows the problem: the body of this lamp is not just decorative, it is a load bearing piece. It holds the lamp together and is under the pressure of the threaded rod.
This lamp could be disassembled and glued with a strong epoxy, but it would be time consuming and it would not be safe. The best thing for this lamp would be to recycle the good parts. The socket, cord, harp, harp base, threaded rod and all other miscellaneous parts should be put in the spare parts bin for the next repair.