Yamaha metal tank

I tried doing a search on the internet and this forum but couldn't find the info I seek. I will be taking possession of a made in Japan Yamaha metal 6.3 gallon gas tank. I don't know if the connection leaks or not. The gas gauge window is yellowed over so you can't see the indicator. Would anyone have a parts diagram of these tanks or the part numbers. I would need the level indicator window, the o rings for the valves, the welsh/core plugs and a new gasket if I have to disassemble it. Also a possible source for these items. I'm assuming since these tank is made in japan that they would be different parts than the USA made metal tanks. Thanks.

Received the tank I got off ebay. It is good shape inside and out except it leaked from around the fuel indicator window. Noticed it when I was sloshing it out upside down removing some fuel while flushing it out. The plastic window was deformed. Hard to explain how it's assembled but I've tried making a new one to hold the molded gasket into shape. That is covered by a piece of glass then sandwiched between the gasket and plastic screwed down. This made in Japan tank is different than a OMC metal tank. There are no parts available for the vent assembly and I'm assuming the whole assembly is replaced. Called Yamaha and they said the assembly is no longer made by them. Kind of wish I just bought a new plastic Yamaha tank now.