While the "scrapings" method will work, as described above, I prefer to take a very well heated sewing needel(or open safety pin) held in pliers and when glowing red, insert(or try to!) in backside of one of the grips. Stag,or bone, or pearl, will not be penetrated, while plastic will show "hole", or crater,like the bullet holes some plasticmilitary modelers make(obviously, don't shove it all the way through.!)
The metal half discs are "locators", just like the full disc plates found on the back of magnas. These will frequently loosen, and DON'T obviously shoot the gun with them loose.
The are also used to partially fit the grips to the gun. With the half discs only held on by something like Elmer's glue, trace their correct location for a good fit, doing one gripat a time. Fully clean the grip area and the half disc, and use one of the miracle glues(but one that has a good 10-15 seconds to align before bonding). I have even used tiny screws on a 45 degree angle to get a more secure fit,on an M-544 convertible .44/40 and .44Mag.
Got lucky, 2 years ago, at a large outdoor market here in Maine, buying a small box lot of virtually new N frame stag magnas, and have fitted a couple ofpairs of them to some of my S&Ws to use as "shooter grips".
Very interesting 1926, in that it has the "rounded top strap" vs. the square top strap that was ordered introduced on 10/17/27.
Thought the frame might be one of the "1917's that S&W "bought back" from the Govt. in early 20's(I have a couple of 2nd Model .44'sbuilt on these frames)- BUT I don't see the "little eagle" peeking out from the nice photo of the grip straps and no evidence that frame was ever drilled for a lanyard loop-as was the case with most "1917" framed .44's I've seen.
Sorry for the long post and enjoy shooting the heck of that 1926!
Bud
