You may have to do some research if your going the "halogen" bulbs due to the bulb holder wether it will fit in the base's, size / thread for the nut / bolt etc, also will it de- value the lamp being altered, personaly i prefer leaving the lamp original when it comes to that and flex.
Hopefully someone will be able to help, maybe state what lamps you are doing or photo will help :-)
I had to rewire my Imperial and a Russian Cosmos Lamp. The trick is twirling the wire strands together and wrapping that around the screws in the direction the screw turns so that the wires stay in place as you go to tighten the screws. Other than that there isn’t much to it.