Well, as far as your spacers you might if you can reuse the old one or if not damaged get the sizes (thickness) of them because as a lot of us 05-06 mastiff owners have found out was that bigdog never kept a record of what sizes were used on which bike. They threw in different size spacers on these year models. I had an issue a few years ago to where my rear tire was off center of the fender and with the help of the guys off here i was able to have a custom set made for my bike to center my wheel up. One of the guys that use to be on here sent me a 1 gallon zip loc bag with all different sizes which I still have, the good news I have for you is that when me and erik come up with the sizes to center my wheel I had to write down the thickness of each spacer to take to the machine shop, I'll look in my notebook today after i wake up, (work 3rd shift) and I'll send you the sizes we came up with. Mr Wright on this form and I believe he responded to you also can make them for you if he has the materials and time. also the rear axle you might not be able to find because out bikes had daytec frames which bigdog stopped using in 2007 when they started making their own frames, daytec went out of buisness a while back, but if anyone has one or can get one it would be donna from HDM, website is bigdogpartskingpin.com.