It's certainly possible. But I agree with Adriatic, I'm not sure that it's necessary. Unless you've already converted your 783 to command control, or you're constantly running it at 16-18 volts to pull a bunch of lighted cars, it's very unlikely that you'll "burn out" the original fluid smoke unit just because it runs dry. That's more of a concern with the newer "wick-type" smoke units typically found in high-end command controlled locos.
By all means do what makes you happy but if it were mine I would keep it original. My $.02.
