It is really hard indeed to gather some of those parts. The reproduction art I needed, marquee, cpo, stickers etc. no problem. Most of that I bought off arcadeshops like MikesArcade, Quartercade or Lizzardlick.
This coin door however, a lot of sellers on eBay just won't ship abroad. Found 2-3 other Nintendo coin doors before this one and sellers didn't want to ship it international. Though I never had any problems with things that did got send out overseas. All arrived in good condition.