If you look at page 2 of this thread you'll see I did some rough calcs as to the volume of a Mk2 spare wheel well.
However, all of these measurements were guesstimates. If you want to take some dims of your spare wheel well I'll be more than happy to calculate the exact volume for you.
However, if you just want confirmation that your spare wheel well is somewhere between 0.8 and 3 cubic feet I can say catagorically Yes to that question.