Bullrock:
Your S&W Model 19 is a beautiful specimen! However, if your picture is accurately depicting the gun-then, I don't see a pinned barrel and this could also mean that it doesn't have a recessed cylinder? If not-then, the value would be less for this gun?
Don't get me wrong, because I love Model 19's! However, consider that Colt is no longer going to produce any revolvers ever again! This is going to make the values of all Colt's to rise! If their values don't matter to you-then, pick the revolver that you like the best?
Although strength might not matter to you-you should be aware of the fact that the Colt Trooper Mark III, is a far stronger revolver than the S&W Model 19! In fact, it is even stronger than both an "L" frame S&W revolver or an Ruger GP100! This is true, whether it really means anything to you or not?
One other fact to consider? You very seldom see any mint condition, Trooper Mark III's-but, you can more easily find S&W Model 19's in pretty nice condition(I didn't mean that this would be easy-only that it would be more difficult to find a mint Trooper Mark III!)! This is one reason why I'm not going to sell my NIB, Trooper Mark III-and, if I had to choose between them, I'd sell my S&W Model 19 first! However, I'm not pushing myself to choose between these two great revolvers(Thank goodness!)so I don't envy you for this tough decision that you are forcing yourself to have to make! Good luck, in whatever you might decide to do? It's never easy having to give up any good guns!
In summary, despite all that I have said above, since both guns are good guns, one thing that you won't need, is to get a heartache over giving up the wrong gun! So, give yourself enough time to ascertain, which of your two revolvers would please you the most(In every way!)over a long period of time-and then, just give up your least liked gun!