So yesterday I picked up my long-lost Zero luggage rack and Givi top box. The top box that I received was the Givi E340 model and did not have a Zero logo on the box. Both accessories were so easy to install that it really isn't worth illustrating how to do it.
To install the luggage rack, all you do is slip on a rubber pad on the end of the rack that protects the plastic tail piece and take off the seat. The rack has two arms that slide over the chassis rails under the seat and two small bolts are supplied to fasten the forward ends of the rack arms to the top of the rails. The holes were a little off and I had to use a set of Channel Locks with padded jaws to squeeze the arms to get the holes lined up enough to insert the bolts. Once started the bolts screwed in to the chassis securely. The rear of the luggage rack arms are secured by the seat holding bolts and this was also difficult getting all of the holes to line up so that the stock seat bolt would connect to the seat "ears". A little fiddly, but it only took about 15 minutes to install. The instructions provided were clear, but really not needed.
Installing the Givi top box plate didn't take any longer. Four universal waffle-plates are provided, but are not needed as the four plate bolts fasten easily through pre-drilled holes in the luggage rack. The bolt heads face upward, with the nuts below the plate. Most of my mental processes went to trying to decide in which direction the elongated holes in the plates that retain the bolt heads to the plastic plate should face. I think they should face lengthwise, so that the rack can slip front or back, rather than crosswise, so the the plate can be positioned side to side.
As it turns out, I had an ($80 at the time) 8-year old Givi E30 in my closet and it also fits on the plate perfectly. I think it fits the profile of the Zero better than the larger E340. Attached is a photo of the luggage rack.