Looking at these grips for my 1860 army

Did you read the review on the product? I know it's one guy, but he did say the one he got had unremovable blemishes, and he could not make it fit.
From what little experience I have, when you replace the grip that came with the revolver, you will necessarily have to do some fitting work, which will also involve polishing and finishing it to precisly fit the gun. Even replacing, say, a Uberti 1851 grips with a new Uberti grip may involve fitting work.
As for these multipiece grips, it appears they need to be glued together with that middle "spacer" piece, which to me is a sort of odd way of producing this, but they may make it that way so you can remove material from the spacer to allow it to fit the width of a particular gun's grip frame.

Tommygunn took the words right out of my mouth about the review. Again, it's just one review but I'd be turned away for that kind of money unless I could find other people that had better luck with them.

I've liked these since I first saw them so last time I purchased my Colt from DGW I grabbed the style you posted the link to. I've never put a rifle or pistol together from a kit so this was my first challenge to do something like that. Yes they have to be glued together and there is some fitting that needs to be done but it was no big deal. After sanding and sanding, fitting and refitting I finally got them as close as possible without too much removal or gaps as I knew how.
As mentioned this was my first build. Not everything was a perfect fit but I account that due to my inexperiance. My main goal was to "age" them so using a file and other items to scratch in cracks, weather the handle, etc. I came out with these. One thing I learned that was dont put your stain on until you have them exactly how you want them to look. After soaking the grips in coffee and then a lite spray of clear this is what I ended up with.
I plan to get another and do the same with it and increase my chances of even a better aged look but I am satisfied so far. Just keep those lilly white grips away from any oil before they are sealed or it will soak in and become a part of the stain which you "dont" want.
I've tried posting this twice and cannot get my attached pictures to show up so I will try again soon. Not oversized pic's, just slow internet service today.

actually being in 3 sections is a major plus, much easier than trying to get the correct fit by carving out the one piece version unless ya are VERY skiled at carving. Of the 6 sets I've changed out on my 3 1861 Colt navies and 3 1860 colt Armies with wood I've always ended up cutting the single piece blank in half then making a new center section so that the center can be fitted correctly and no not even with consecutive serial numbered guns can ya get any interchangability in grips from one gun to the next..... the 1861s are the worst as the grip frame is silver plated and so cannot be sanded to match the grips etc... (the original colts had the grips fitted for thickness then the single piece grip was installed on the grip frame and then the wood/metal were sanded together for a perfect fit) 3 pices is the only possible way I can see the grips mentioned above being properly fitted as opposed to the expense of sending the gun itself to a custom grip maker to have the grips made to the specific gun etc.....

A real bargain if ya have even the slightest clue of how much is involved in properly fitting a one piece grip to a colt!

Aeagle grips makes beautiful grips for C&B revolvers. It's more expensive, and you may have to send them the gun, but they do beautiful work.
www.eaglegrips.com