I think it w/b a mistake to associate carved pearl grips with W&K as being the source, unless you have a Smith that letters to them. Because they were more readily available from the likes of Sears (see image) and common on Colts as well. I'm a gunleather man so had to learn more about the grips of the old SA and DA revolvers because of the Tom Threepersons and his holster; and Jelly Bryce and his holster.
Likely they were always sourced from out of the country, such as Mexico or even Asia, anyway. It is my understanding that if pearl or ivory grips have the Colt medallion, they are factory; and if they don't, then they are aftermarket of the period. These, and nickel plating, were common aftermarket add-ons by the selling dealer; like seat covers and radios used to be on cars.
Tom's two SAs have a combination of ivory and pearl each (one or the other on a side); which tells us that these were not up to the assignment of LEO use. Ranger Capt. Hickman has carved ivory panels on both sides of his two SAs, worn at the same time; while Ranger Capt. Gonzaullas' 1911s had his carved as left/right, and wore them together that way (a dual safety on his left pistol).
This is Jerry Campbell's W&K Smith; Jelly Bryce had an identical one. The introduction of the .357 Magnum in 1935 (not a coincidence of the '35') caused both men to switch to 3-1/2" pre-27s, in which case they could have switched the pearls over to the new pistols.
