Another obvious visual difference between the Dragoons and the Walker, is that the Walker didn't have a latching loading lever.
Yep. Instead of a retaining latch, the Walkers, Dragoons, and newer Patersons that were retrofitted with loading levers had a single leaf spring inside the lever recess that kept the lever flush against the barrel. However, upon the recoil of firing the weapon, the lever is still prone to flipping downward. Sometimes the plunger will wedge itself into a chamber and lock up the gun when the shooter tries to cock the gun for a next shot. Not a good situation to be in when you are facing a band of hostiles on the gallop and have to react instinctively.
The modern reproductions of these pistols also exhibit these characteristics. Many new shooters think that it is a manufacturer's defect but they actually reflect the design flaws that went into the early Colt revolvers. The earliest production runs of the 1836 Paterson even had fully exposed nipple faces enclosed by the cylinder wall outside. There was no metal barrier separating each individual nipple. If the shooter had not sealed the capped nipples with tallow or grease beforehand, upon the first shot, flame and hot gas blowback from the chamber being fired was prone to racing across the entire rear of the cylinder and setting off all of the other chambers at once, causing the cylinder pin itself to be pulled loose and the bewildered shooter left holding just a handle and a smoking frame in his hands. Colt quickly learned from this issue and all subsequent revolvers had each chamber nipple isolated in it's own three sided recess that opened outward to allow easy capping.
Many period shooters as well as reenactors/competitors having to deal with the unlatched loading levers of the Walkers and Dragoons often employ a piece of twine or elastic band. One of the things I made in significant numbers for "Walker fixes" was a simple U-clamp bent from a piece of thin flat stock that went over the barrel and the loading lever and secured under the barrel with a bolt and wingnut. I sold a good number of these at N-SSA and CWSA shoots. Now, full loads from these big guns would not flip the lever down and jam the works.