No matter what old pickups you have and if you don’t like the sound, always try and keep the pickup original. I would try find a source to get another pickup that may be broken but could be wound to the sound you are looking for. A good pickup builder usually has supplies to make various types of custom pickups. Every year there are more and more vintage guitar & bass pickups that become destroyed.

Several years ago a young player was given a 58 Stratocaster from his father. He came me and wanted to put humbuckers in it. I told him it was a bad mistake and try to get another inexpensive guitar to modify. He said he would look into it. Several months went by and I saw him at a local club. To my amazement he had chisled the body out with a screwdriver and hammer (beyond the pickguard) and put in three humbuckers! I couldn’t believe it and he said “nobody wanted to do it”, so he did it himself!

If you want to change your pickups, please buy a new pickguard and keep the original in a safe place. You may decide to go back to it someday. And if you decide to sell it, keeping the original parts will make the buyer quite happy, and bring you top dollar.