When acquiring my 4x5 Crown Graphic kit, I made sure that each piece was as close to brand new as possible. And cleaned up those pieces that weren't until they looked like they were. Not because I'm looking for attention. But because I want the camera to generate attention. Participatory portraiture. Not stealth portraiture.
Often the first question asked is "Is that a replica?" "Nope. It's the real deal. A mid-1950s model press camera. Works beautifully." "But it looks brand new!" And at that point I've got 'em hooked.
I do make a point of knowing a little of the history for each camera, and use that as part of my answers to questions. For instance, famous photos made with it that they might recall. Relating interesting stories and anecdotes serves to help put people on a more comfortable peer basis with you. You're simply telling them a fascinating story about a cool-looking old camera.
I do often fib a little by stating that it's a new-to-me camera I'm just trying out. Harmless, and puts people even further at ease, since they're then obviously not the primary "target". Once they are comfortable, you'd be amazed at how many had grandfathers or great uncles that "used one of those" as newspapermen back in the day.