G'day again from Australia!
Went on line to Bunnings and found they have D.I.Y. advice, so looked up cork flooring rehabilitation.
Useful advice on sanding, grades of grit to use etc.
Product recommended is an oil based polyurethane to give a "hard wearing glossy finish".
There is a water based product for about 1/4 the price, but its 'blurb' states for door mouldings and outdoor furniture, so I don't think it would be suitable for the floor!
We don't have Bunnings in our home town, but one an hours drive away, so I will enquire next time we go there.
The old surface has very slight pit marks in it in high wear places, so I might see what information I glean face to face.
Will be interesting to see if they can help with the wifes query, as to how long the smell hangs around.
I am fairly confident in using machines, but if I make a real mess [unlikely] then it may be as you suggest - time to get a new floor!
Cheers.