That Steve Earle action is sweet looking. If it were me I would simply never get the build done because I wouldn't be able to make up my mind on which to use.
"Hey Tom, why don't you make all of them" is not an acceptable reply due mainly to mortgage payments, food, etc.
Someone around here had a #1 with the side lever and I am still looking for the time to fit in that as a project.
Just as an aside, I think that it is pretty interesting that the .577 barrel only needs mauser threads. Really expected something different but lets hear it for low pressure and modern steels.