Question for any all.

I've got a photo of my grand mother from 1919 or so. Its a great 126x20 b&w but it has subtle coloring in some key spos. Does anyone know how they used to do this? I would like to try to duplcate a photo like this.

I would guess that it was hand colored.

that's my guess as well.

For a start check out https://en.wikipedia.org/wiki/Hand-colouring_of_photographs

Then Google hand coloring oil photos for lots more information.

Hand Coloring was popular before WWII, my mother still has Her & Dads wedding portrait hanging on the wall. They can look really good if done right.

We were still using hand colored oils to color portraits in the 90's. usually these prints were made as replacements for color portraits from the early 70's that had faded badly. The were more than a few different ways to hand color, you could go anywhere from subtle tints (maybe done with water color, chalk or oil pastels) to full blown heavy oil over and entire print. Prints were usually done on Ektalure and Selenium toned to brown, then dry mounted and sent out to our colorist who had been doing heavy oil since the late 40's. Marshall's made oil paints in both tubes and colored pencil even had special shades to match US military uniforms without blending. Veronica Cass also offered oils and other colors and the Veronica Cass Academy taught retouching on negatives and prints.