I'm not in an immediate panic to source a tank but it will hold up most other work. I could look at sourcing new shocks to get the bike's stance closer to right but I think that's a bit cart before the horse.
I've some work to do on my other project bike over the weekend so I'm in no immediate rush.
So coincidentally I ordered a replacement tank for my other project bike - a Yamaha XJ600. Turns out the red is a near perfect match. I'll size it all up at the weekend but after a quick measure up with the tape measure I think the XJ600 tank may fit quite nicely. It's not the world's most beautiful tank but it's a big improvement in many ways. It doesn't rise as high above the front mounts, it is approx. 4 inches narrower at its widest point. It's also longer but I actually think that for someone my height that may work well if I go for clip-ons.
The KZ is sitting for now pending sorting out its paperwork and while I try and resolve an electrical issue on the XJ - pic of the new tank sitting on the XJ also attached.