I have heard this discussed before. I do not know if there were any ever made or not.
But the best discussion I heard was the discussion about the cylinder. It is not big enough for the 41 mag.
that told the story for me.
Reno;if you ever come across an Army Special,or an Official Police chambered in the .41 Colt ctg.(dropped in 1930 from the O.P. line) you will graphically see about the thin forcing cone.
I have a 1920 Army Special,and the cone only is .055 wall thickness for a .403 diameter bore. Deduct a couple more thousands from this if you went to a .410 bore for a .41 Magnum,and you'd be "marginally thin" for a ctg. of the .41 Magnum pressures.
Not known by many,is that Henry Fitzgerald("Fitz") of Colt wanted to see a speeded up version of the old .41 Colt in the 1930's. A ctg. called the .41 Colt Special was developed,which had ballistics around 1000-1200 fps with a 200 gr.bullet of slightly over .400 diameter. The E frame,or ".41 Frame" guns like the Official Police,would NOT stand up to the firings. Several big New Services were chambered in this,and worked fine-BUT-Fitz was after a smaller revolver than the New Service,that could already be had in "big bore" chamberings such as the .45 Colt.
BTW,the old .41 Colt is a smaller diameter case and bullet than the .41 Magnum,case being around .406,as were the original heel bulllets(later replaced by hollow based .386s to fit inside the case fully & expand in the .403 or so bore.
My "dream gun" has always been a "357" Model Colt chambered in 10mm,and I had plans to have this done in the late 80's,but consultations with several nationally known gunsmiths,convinced me that BOTH the forcing cone and the cylinder were to "thin" for safe use of 1200 fps. rounds-and the 10mm has a SMALLER diameter case than the .41 Magnum,as far as removing less metal from the cylinder walls;so I shelved the "idea".
Whole argument of a .41 magnum in a E/I frame Colt,with SIX shots,reminds me of those concerning the original SAA frame size as being "OK" for .44 Magnums.
Then,of course,we run into the "argument" of stronger metals today vs. "then"-such as S&Ws scandium and titanium(which has had problems with finish retention and machining-if I am to believe what some others are bitching about on "the other side"!)
I saw one to these modified pythons in Louisville. The conversion "looked" good. It would be an interesting piece to own just for the conversation, but I would't fire it. The person who was displaying it had a sign on it saying it was extremely rare. There was nothing about it NOT being a factory original so I walked on by.