Mike - why couldn't a copy of a product that was made 150 years ago be made as good as or better than the original? Modern steel is better, modern machine tools are more consistent, tolerances are able to be held much closer, engineering has progressed, etc. Sam Colt changed his design over the years, why can't that continue? You change Colt design when you work on them now don't you?
Are you sure that the arbor bottomed out on the original design? Are there any original blueprints showing that to be the case? On the few originals I've seen, the end of the arbor didn't appear to have been machined to some specific length, it was sort of roughly tapered.
As far as the sun being hot, it needs to be hotter at least for us in Wisconsin.
Jim, "tuning" is / should be an enhancement to the action, the "shoot-ability" or operation of the revolver. The idea is to extend the parts life and overall life of the revolver. Dragging back an 8 lb. hammer may be fun to some but most find 4 lbs to be much more enjoyable. Everyone marvels at the Ruger coil spring action and that's exactly what I bring to the "rest" of the SA crowd. Parts independently sprung are more "adjustable" instead of over sprung which shortens the life of the spring and the part /parts.
To answer your question, yes I redesign the springing of the parts, the way the parts interact with each other for more efficiency of operation . . . but it would be foolish to interfere with or take away the structural integrity of the revolver . . . which is why the arbor setup is so important. It's the very "backbone" of the open-top design.
Maybe you missed my post about how all the originals I've handled and disassembled for photos have had correct parts and such. The arbors did in fact bottom out and so did the one original that I did get to convert to coils, ad an action shield, action stop, bolt block, adjustable wedge bearing. It's an all numbers matching 1860 Army made in 1863. It's now heading to Turnbull for a refinish.
That being the first original I've ever drilled and tapped showed me just how much better material our copies are made of. Because the originals were built to "design", folks still shoot them today. The modern examples, even made of better materials, won't last because of inadequate adherence to design.
Some folks may want to debate the arbor fit but there's plenty of infallible proof ( from others and my own and even a manufacturer) it's absolutely necessary for a correct Colt platform build. Shooting 23Kpsi ammo in one without proper fit will "absolutely" tear it up!!
And I agree, you guys need sunshine in "cheese head" country!!!
Mike