Maybe this came with the unit when new, like the strobe pattern replacement donut, but was forgotten about by the time the original owner gave it to me decades later.

My suspicion is that while this International version only requires a fuse re-positioning to accomodate voltage changes and a change to the pattern for the strobe images, it requires a different wheel somewhere in the drive system to overcome the power supply cycle difference. But even with it set as low as it can go, the speed is too fast, with both 33.3 and 45 rpm settings. I have checked underneath to make sure the minor speed control adjustment is able to travel as far as it physically can, and it is functioning as designed. I was about ready to start the tweaking and new plinth building process, but I did not expect to encounter problems with the speed after moving the voltage jumpers (fuses) to their correct positions.

It just goes over the original 50Hz strobe donut sticker already on the underside of the platter. This paper donut sticker originally came with the unit, and was given to me by the original owner when he gave me the turntable. The only change I have made is to attach the 60Hz strobe pattern donut to the underside of the platter. With one neglible exception, everything is still original on this unit, including the magnificent plastic-&-cardboard plinth. Everything worked fine in England where I acquired it, but now that I have finally gotten around to unpacking it and coverting it for North American use, it is playing too fast. The Synchro-Lab motor in inscribed with the usual international blessings for 120 V/60Hz and 240V/50Hz, and the power cord inputs have little copper wire jumpers (what used to pass for a fuse in Britain) with guidance diagrams - hence the International designation. My Garrard Zero-100 International idler wheel turntable won't slow down to proper speed.

Garrard zero 100 plinth