I have a Pearl II and have checked out this Ebay item (the Pearl III) many times.
The Pearl II has a coupled RF and a beautiful coupled DOF/distance scale on the top (it's a window where the III has a film type reminder). The downside is red window winding, no x-synch (it cannot be converted), and a slower lens. I'm not sure that red window winding is necessarily the worst thing in the world; modern films are thicker, and some older auto-stop mechanisms don't handle them well.
Hopefully the III does not have the same problem the II does, which is that with modern, thicker films, you need to make sure you do not allow the winding knob to ride out of the spool and slip. As you turn the key, you need to keep the key pressed in toward the body. This is due to the leaf springs that are used to hold the takeup spool in place. Modern cameras have locks that prevent this riding. Is that the function of the lever under the knob on the III?
Dante