technically you have to use 2 sets of spindles.... on set you machine the back off, the other you machine the front off... set them up square and true, weld them together... and hey presto!! Even I would think long and hard before I did something like that!! And even then I'd probably just buy a set of cast ones
how do transporterhaus manufactur theirs as they state not welded? Are they new from billet or casting>
I wouldn't do them myself anyway, just wondering if people do make their own. If I were to cut and weld, I'd machine a step in the spindle and machine a socket in the back plate then weld both sides of it.