I love that mature male, but its not a RCF, often called "Usambara"
Could you take some clear shot of the abdomen of your Pterinochilus sp. „sjoestedti” juvenile, from different angle. Also, when it molts, a clear shot of the spermathecae, if its a female and if they're developaded of course.
It would be great to have a another view (front view) of your Pterinochilus sp. abdomen.
This said, these marking are pointing Pterinochilus chordatus, or Pterinochilus lugardi. But, looking at its coloration, Im almost sure its a Pterinochilus chordatus. Everything will be clear with the exuvium.