Just saw this on ebay. I don't need it, but not many of these around
https://www.ebay.com/itm/YAMAHA-NOS-28V-24110-00-02-XZ550R-VISION-1983-XZ550-XZ-550-GAS-TANK-WOW/233313681899?hash=item36529441eb:g:z40AAOSwJNpdVLhm (https://www.ebay.com/itm/YAMAHA-NOS-28V-24110-00-02-XZ550R-VISION-1983-XZ550-XZ-550-GAS-TANK-WOW/233313681899?hash=item36529441eb:g:z40AAOSwJNpdVLhm)
Just be aware that this is for a US '83 and needs a different petcock and has a hole in the inner saddle for the fuel level sender.
That seems a decent price for unobtanium.
Hah! I just took a closer look at that tank. The "decal" stickers are coming off and cracking. So it looks good from a distance, but needs a paint job. That would be ideal for repainting with the 'fish net' stocking method to make it look like scales on the skin of a very large snake. I have been mulling this idea ever since I saw that discussion where one fellow painted his tank red, over a large fish net stocking, then the stocking is removed leaving the lines making the surface look like scales. I think it would take a bit of practice to get something like that to have the intended results.