Cary,
The technical aspects of converting the bolt stop were not that hard. Welding on a Springfield action was challenging. I did not weld it myself but used Peter Nagel of Restorative Welding in Oregon, IL. We had some issues in regards to porosity that peter felt were related to the original heat treating of the actions. Eventually the welding came out pretty darn good but it took some determination. I have one more action in progress that is a personal gun. If I were to do another I might look at going about it slightly differently but to be honest, hunting down an original square bridged commercial mauser would most likely make a bunch more sense.
Steve