In various dungeons, or lairs, you could find some pieces to a sword, or a bow, and there would be different types, of course. Maybe there could be a elven blade, a glass hilt, etc. Then for bows, different types of strings, the ends of the bow, and so on. Then each feature would have an affect on the weapon, how fast you swung, how fast you draw back the bow, and the opposite, which is the strength of the weapon. Then as you continued farther into the main story-line, there could be parts that were related to the quest that you find them. For example, if this feature was in Oblivion, there would be a magical looking blade, or hilt for a sword, or for when you finished the Dark Brotherhood, there was an evil looking piece.
What does everyone think?