Apple Valley made vinyl doll kits that you could assemble for yourself. Choose your face style, body style, skin tone, choice of eye color, wig etc. The kit included the ties you needed to assemble the doll. Just add polyfill and plastic beans for weighting. The doll kits were extremely popular and many cottage industries sprang up as local doll artists assembled and sold the readymade dolls.
Later, the Apple Valley company transitioned the making reborn doll kits. Reborn dolls are extremely realistic and look like real babies when completed. Apple Valley didn't invent the Reborn concept but they were very instrumental in the development of the industry.
You can purchase their doll kits at Apple Valley Doll Works or Secrist Dolls websites. Secrist Dolls focuses on the Reborns and Apple Valley Doll Works focuses on play dolls.