I purchased a spare wheel on Ebay so not the full kit as Honda supplied but I have the Jack,foot pump and odds and sods inc Tools stored etc.
I found that if you put wheel off centre and used the bolt and cup etc in a wheel nut hole to safely secure it.
It provided more space to accomodate the above accoutrements.at the side by placing Tyre pump in box into centre of wheel,it provided substantial support for the cardboard floor that is supplied.
Hope this is of interest and perhaps some help.
You need to move wheel around abit to maximise the available space.
Good luck.