Back in the 70's & 80's I did a lot of retouching mainly B&W prints,but occasionally colour prints for others. Also I did a lot of hand colouring work, using toners, chromogenic processes and dyes as well. The company did a lot of composite work, often using lith masks, opaque, Ruby lith tape. I've always used proper retouching dyes like Spotone, and the Paterson Colour dyes.
In recent years the only major retouching I've done was myself out of an image A LF multiple flash exposure image in a manganese mine, someone else lit me up - there were 4 people painting the cavern walls with light making 20 full power flashes each. Took a bit of retouching but it's invisible, just done with Spotone.