Doing a proper "CLA" on a SLR camera can easily take more than 5 hours of almost-non-stop, no-interruptions-allowed work. Or days. This will involve stripping the camera completely, cleaning (which might involve ultrasonic cleaning or removing all kinds of stubborn gunk), relubing, checking shutter curtain times and readjusting tension, renewing curtain brakes if there are bounce problems, checking flange-to-rail length and paralellism, checking or readjusting focusing screen for correct focus, same for mirror angle, readjusting metering for the whole range (dark, middle, bright EVs), Then assembling everything again, some parts have specific positions and tolerances... If the camera has an AE circuit you also nee sure it's exposing correctly, no matter what the meter reads. And then there's the light seals topic, which isn't trivial on some machines. I'm sure i'm leaving things out right now.
Just multiply time for a reasonable hourly rate and you'll have an idea of how to charge.