This is a very interesting question, and one that I have been thinking about recently.
All of us enjoy props and other collectibles from movies for various reasons. Some just want to "hold that thing in their hands," others spend hours, days and weeks meticulously researching a particular item so that they can create the ultimate screen accurate version.
I think this is very much a "to each his own" sort of thing. I have certain props that I want to create that I certainly want to weather and make it look like a screen accurate version. Others, I want to look like I just bought it right from the weapons shop at Mos Eisley.
So, to directly answer your question. I want my lightsabers to look brand-new, my DL-44 to look beat up all to hell, and my phaser to look like Scotty just handed it to me.
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BLEEP!