Ah, the age old question of preservation...

So I have a nearly stock 1985 Trek 560. The only thing besides tires and bar tape that's not original to the bike is the rear brake lever. I have been trying to find a Suntour Cyclone non-aero brake lever to replace the missing one but with no luck. So here's my question: Should I replace the brakes with aero levers since one original is missing anyway?

I plan to ride this honey a lot and though I don't mind riding vintage, I wouldn't mind having a sleek cockpit.

Any advice from the Forum would be great.