Mechanical Jewel?
Well, i don't have experience with Minoltas or Pentaxes so can't really include, but resorting to Nikon and Canon, let me first said that a jewel should probably have an HORIZONTAL shutter since for the "classic mechanical cameras" era (1950s-1970s), the vertical shutters were rougher, with more vibration. Also, apply pressure finger on a vertical shutter and you can wreck it, while the same, on a cloth or metal horizontal shutter, will do almost no harm.
So... here's my experience after using many Nikons and Canons:
Nikon F: Mechanical jewel, externally, because the build quality is so high. Internally, as one poster above said, it is a "clock tower". Not sophisticated but solid, reliable and smooth enough.
Nikon F2: Unquestionably a mechanical jewel internally. Sophisicated, reliable and very very smooth. The external build quality is a bit inferior to the Nikon F, in my experience.
Nikon F3: Internally a mechanical jewel as well, the mechanism is really really smooth, perhaps even smoother than the F2. Sadly, it relies on electronic shutter timing, so it's not really a "mechanical" camera. And the F3 electronics' reliablity are controversial.
Canon F-1 New: Externally a mechanical jewel, the build quality and solidness is higher than the Nikon F and F2.
Canon F-1: The winner for me in the "jewel" category. External build quality is higher than the Canon F-1 New and Nikon F AND F2, while internal mechanics are as smooth and refined as the ones in the F2.
I would NOT include the Nikkormats, despite being great cameras, because their operation (in terms of vibration) is definitely not as smooth as the horizontal-shutter Nikons.
I would also NOT include the FM or FE cameras because the build quality is not so high compared to the cameras above. FE2 or FE3, don't know.
It is important to note that I own all the pro cameras listed above save for the F3 (which I sold, but used a lot).
Finally we should include the Leicaflex original models as well. They are mechanical jewels!! Sadly, reliability is not on par as with the cameras above. Most reliable would be the Nikon F hands down, over ALL the other cameras listed here.
But thus, i declare, the original Canon F-1 as the overall winner on the mechanical jewel category. Sorry Nikon fans, you need to own a F-1 to understand. Canon wanted heavily to surpass the Nikon F in build and mechanical quality and they achieved that with the F-1. I still think that a Nikon F2 is a better camera from an users' point of view, though.
