Right, so I've got everything, the bolts, the brake discs/drums, shoes and pads and the alloys.

So what do I do now. Not put them on.
Figured that since all the brakes are still good and the tyre tread on the steelies is also good, I will keep them on til spring arrives. Dont want to put them on before the snow comes down and wreck them into a curb.

I hate wheel bolts. A stud conversion makes much more sense.

BUT, I think the mistake you may be making is measuring end to end. The convention for wheel bolts is to measure from the threaded end to the point where the taper begins.