There’s not a lot of information on the web about the differences between the two versions of the B67. A list of functional differences is available here, but the visual, just-glancing-at-this-machine, differences aren’t mentioned anywhere (not that I could find). The machines just say “Studer B67” without marking which version it is, so if you’re not familiar with these machines you’ll have no idea which one it is. According to my friend from the Studer list, there are a couple of visual differences that set them apart:
1. The Mk II machines have vertical grey plastic bars between each pair of big and small rollers, and the Mk I machines don’t.
2. The Mk II machines have a screw on the top of the timer roller (big one on the right), while the Mk I machines don’t.
These two photos illustrate these differences: