Pretty much any revolver with a swing-out cylinder is considered "modern style" by S&W, the "old style" refers to top-breaks. With the exception of some very minor changes, your 29-3 works the same basic way as a Triple-Lock made in 1907 or a brand-new 629 made yesterday. The barrel, cylinder, trigger, hammer, ejector rod, and thumbpiece are all in the same places and are manipulated the same way as they've always been. The reason that S&W's manual seems generic is because it's much simpler and easier to write one manual for all models and then add sections for models that are exceptions.