I think that the stories about "problematic" assemblies in cameras are a bit of a distraction for most current film shooters who, while possibly professionals like yourself, are certainly not using their film cameras in the way professionals once did. We're more like casual hobbyists, if you'll forgive the phrase. Pros, back in the day, absolutely hammered their cameras, and some assemblies failed before others or just wore out. Your 1600 is in beautiful shape, and was probably used by a well-heeled amateur. It reminds me of the Bronica S2 vs. S2A horror stories about stripped brass winding gears. There are plenty of S2 cameras chugging along just fine, since they weren't hammered, and like your 1600, will probably continue to do so if treated with the respect they deserve. Isn't your Bronica the S2?
You've already given the 1600 a CLA and the pampering it should have. Just use it and enjoy! Now, if I could just follow my own advice and stop worrying about every potential failure that my old cameras might see...