You are in luck. The Gyordec and all of its variants is very easy to ship as it can be fully broken down. As a former owner of an Gyro and an Orbe I've moved them across country and from the UK to the US (albeit all in the original box I have to say) .
The links below give details on assembling a Gyro -- simply reverse to break it down. Then have your seller pack each part independently. The hardest will be the plinth and the cover, perhaps have those shipped in a separate box, or at the least have foam or similar cut to fill them out. All the other parts are pretty easy to pack independently.
What I cannot speak to is the arm. Ideally remove the arm and pack it in something like a separate hard shell case (link for a good one that should be the right size below), if they do not feel comfortable removing it then you have the issue of a) securing it to the sub platter so it does not move and b) packing the awkward combination. I'd have them remove it if at all possible -- I always shipped mine with the arm on but again it was in the original packaging
Assembly details (for a spider so the original is a bit different but should give you an idea, also the details of the springs in an early Gyro may if I recall be different)
http://www.angelfire.com/music5/michell_gyrodec/step_by_step/manual.html
Ideal packing for a 9-10" tonearm (Nanuk 910 hard case)
http://www.adorama.com/NA9100007.html?hotlink=t&svfor=5m&gclid=Cj0KEQjwt763BRDZx_Xg3-Pv2cABEiQAoDfeGOEz-U7xV2Q86cg3gtSz7M1idkNBt7iooZjnHLkTRAEaAm1n8P8HAQ
The links below give details on assembling a Gyro -- simply reverse to break it down. Then have your seller pack each part independently. The hardest will be the plinth and the cover, perhaps have those shipped in a separate box, or at the least have foam or similar cut to fill them out. All the other parts are pretty easy to pack independently.
What I cannot speak to is the arm. Ideally remove the arm and pack it in something like a separate hard shell case (link for a good one that should be the right size below), if they do not feel comfortable removing it then you have the issue of a) securing it to the sub platter so it does not move and b) packing the awkward combination. I'd have them remove it if at all possible -- I always shipped mine with the arm on but again it was in the original packaging
Assembly details (for a spider so the original is a bit different but should give you an idea, also the details of the springs in an early Gyro may if I recall be different)
http://www.angelfire.com/music5/michell_gyrodec/step_by_step/manual.html
Ideal packing for a 9-10" tonearm (Nanuk 910 hard case)
http://www.adorama.com/NA9100007.html?hotlink=t&svfor=5m&gclid=Cj0KEQjwt763BRDZx_Xg3-Pv2cABEiQAoDfeGOEz-U7xV2Q86cg3gtSz7M1idkNBt7iooZjnHLkTRAEaAm1n8P8HAQ