You go to the site in google chrome which has the translation stuff in it, then click the yahoo auction link (goody-japan is in english anyway so thats easy) which takes you to yahoo auctions in japan, wait for it to translate to english, then select cars / motorcycles from the acution type drop down and search for Z360. Remember they had both aircooled z's like ours and then later watercooled ones which look similar but had many different parts inc bodywork as they are based on the longer life floorpan.
Remember they didn't get the Z600 in Japan, there were a few N600E (expoprt) version but these are a rareity. There around about 3-4 pages of parts maybe 60-80, of various things.
I have a Japanese bumper and several UK bumpers, I'm sure they are all identical and look the same as the US ones (albeit without the additional rail fitted).
I can't find pictures or part numbers for the Japanese bumper brackets anywhere right now but i think the bumpers are the same just with shorter brackets that tuck the bumper into the body more. You could try by removing your bumper, take the brackets off then hold it up and I think you'll find it follows the profile of the bodywork.
USDM Z's appear to have extra brackets on the body to take the indicator lights mounted up through the grill. Euro cars had flat grills like the JDM cars but with early civic style turn / side light units mounted on the top of the bumper each side. The JDM cars had lights under the front bumper where we have those metal infill panels. Like these
For the rear bumpers there appears to be use 2 types the flat more recessed version and the later more rounded type that stick out maybe half an inch more from the body. Some markets also had overriders that bolt into the rear corner bumpers.
Hope that helps, there is the LHS light setup above and at least a RHS lens at the moment. To bid you register, lodge a deposit via paypal and then fill in the bidding form on the goody-japan website and they do the rest.; They send you a paypal invoice when they have the parts inc all their fees and shipping etc.