Razor e300 rear wheel assemnly

Designing a homemade ebike.. I need to know length of axle for e300 rear wheel version 1-35 with 10 inch wheel..Also same dimension for v5-v27 for the 9 inch wheel. All indications are that they are MUCH narrower than the later versions and may fit between traditional 18-20 inch kid bike forks much more easily (is not having to spread the bike forks so wide ) Any help would be appreciated.