Maybe Drew (moriwaki man) can sort you out.
We did a search about 2 weeks ago, through Honda Japan and apparently there are no full sets (9 piece) for the 21 Rothmans kit.
For the 28 there are about 30 scattered all over Japan. Price is about 200k JPY.
That auctioned tank is there for quite a while. Surely that means that 75k is too much...
John