Back in 2000 when Ruger discontinued the .41 Magnum Bisley I couldn't find one anywhere. Since I really wanted a stainless ayway I had Gary Reeder use a stainless frame and built a 5 shot 5.5" with his Gunfighter gripframe which is just a little different from the Bisley frame.
The barrel and cylinder are much heavier than stock but it will handle any load you want to put in it...
Your ideas of a case hardened frame and Bisley gripframe sound real nice. Since the barrel is being shortened you may want to get a replacent front sight base that will take easily interchangeable blades and Bowen rear sight.
Bob