I tried the 45-90 route and just went back to using 8X56 brass. To neck size I use a 325 WSM sizer which is large enough in the body that it only works the neck. Before I found a set of used 8X58 dies, to F/L size, I would just touch up the brass with my 8X56 dies (it is 8X56 brass), but it was many firings with neck-sizing before that was necessary.
I imagine you could do the same thing with the brass you've made up with 45-90.
More info here: http://castboolits.gunloads.com/show...n-a-Swedish-RB