Fun fact: if you take a Ruger New Vaquero and retrofit the hammer to the lower "SuperBlackhawk" type, OR buy one with that hammer already mounted by Ruger (the "SASS Specials" sold in pairs, or the short-barrel Montado), the "thumb reach" and other ergonomic properties will exactly match a bone-stock pre-WW2 Colt SAA. To within a millimeter or two at the outside, as far as where the tip of the hammer was hitting my thumb in my test. I was comparing my 2005-era NewVaq357 to a 1907 Colt 1st Gen and another 1st gen of unknown year but definitely a black powder frame (pre-1895).
The NewVaq starts life as a clone of the Colt SAAs made after WW2 (2nd gen and forward) which is oversize from the originals and has a higher hammer.
The reason I went to a lower hammer was to get the tip of the hammer to exactly hit the middle joint of my thumb at the start of the cocking stroke. This lets me push the hammer down in a very positive fashion instead of "dragging it down" with friction on the pad of my thumb. The latter technique can fail under stress, blood on the hand or the like. Hooking the thumb fully over the hammer is just more reliable.
The SBH and Montado hammers are the same casting but with different thumbpad checkering patterns. The difference is mostly cosmetic. The Montado and SASS Special hammers are diamond-checkered with a border and have an "old west look" (sorta), while the SBH is just sideways grooves. I like the SBH type because I slip my thumb off the side of the hammer at the end of the cocking stroke, dropping it to a "thumb on thumb" shooting hold. I don't use off-hand-cocking and consider it a really bad idea overall.
If you can't afford a Colt and/or want a carry SAA with a modern safety but period-correct handling, a NewVaq with an SBH or Montado hammer makes a ton of sense.