Are you getting any error messages? Based on this line:
[BODY_DETAIL_PLAN:VERTEBRATE_TISSUE_LAYERS:SKIN:MUSCLE:BONE:CARTILAGE]
it looks like your creature is putting muscle where fat should go, bone where muscle should go, cartilage in place of bone, and nothing where cartilage should be. Since there's no ARG5 given, DF will probably default to using the first tissue it can find in the creature definition, which is going to be skin.
What you want to do is something like this:
b_detail_plan_pinky
[OBJECT:BODY_DETAIL_PLAN]
[BODY_DETAIL_PLAN:PINKY_TISSUE_LAYERS]
[BP_LAYERS:BY_CATEGORY:BODY:ARG3:50:ARG1:1]
[BP_LAYERS:BY_CATEGORY:BODY_UPPER:ARG3:50:ARG1:1]
[BP_LAYERS:BY_CATEGORY:BODY_LOWER:ARG3:50:ARG1:1]
[BP_LAYERS:BY_CATEGORY:GROWTH:ARG1:1]
[BP_LAYERS:BY_CATEGORY:ARM:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:ARM_UPPER:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:ARM_LOWER:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:HAND:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:LEG:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:LEG_UPPER:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:LEG_LOWER:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:LEG_FRONT:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:LEG_REAR:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:FOOT:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:FOOT_FRONT:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:FOOT_REAR:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:HEAD:ARG3:50:ARG1:1]
[BP_LAYERS:BY_CATEGORY:NECK:ARG3:50:ARG1:1]
[BP_LAYERS:BY_CATEGORY:WING:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:TENTACLE:ARG3:50:ARG1:1]
[BP_LAYERS:BY_CATEGORY:CLAW:NAIL:100]
[BP_LAYERS:BY_CATEGORY:PINCER:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:TAIL:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:STINGER:ARG4:100]
[BP_LAYERS:BY_CATEGORY:SHELL:SHELL:100]
[BP_LAYERS:BY_CATEGORY:EYE:EYE:100]
[BP_LAYERS:BY_CATEGORY:TOOTH:TOOTH:100]
[BP_LAYERS:BY_CATEGORY:TUSK:IVORY:100]
[BP_LAYERS:BY_CATEGORY:NOSE:ARG5:4:ARG1:1]
[BP_LAYERS:BY_CATEGORY:PROBOSCIS:ARG5:4:ARG1:1]
[BP_LAYERS:BY_CATEGORY:ANTENNA:ARG5:4:ARG1:1]
[BP_LAYERS:BY_CATEGORY:MANDIBLE:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:EAR:ARG5:4:ARG1:1]
[BP_LAYERS:BY_CATEGORY:LUNG:LUNG:100]
[BP_LAYERS:BY_CATEGORY:MOUTH:ARG3:10:ARG1:1]
[BP_LAYERS:BY_CATEGORY:BEAK:ARG4:100]
[BP_LAYERS:BY_CATEGORY:RIB_TRUE:ARG4:100]
[BP_LAYERS:BY_CATEGORY:RIB_FALSE:ARG4:100]
[BP_LAYERS:BY_CATEGORY:RIB_FLOATING:ARG4:100]
[BP_LAYERS:BY_CATEGORY:HEART:HEART:100]
[BP_LAYERS:BY_CATEGORY:GUTS:GUT:100]
[BP_LAYERS:BY_CATEGORY:LIVER:LIVER:100]
[BP_LAYERS:BY_CATEGORY:STOMACH:STOMACH:100]
[BP_LAYERS:BY_CATEGORY:GIZZARD:GIZZARD:100]
[BP_LAYERS:BY_CATEGORY:PANCREAS:PANCREAS:100]
[BP_LAYERS:BY_CATEGORY:SPLEEN:SPLEEN:100]
[BP_LAYERS:BY_CATEGORY:KIDNEY:KIDNEY:100]
[BP_LAYERS:BY_CATEGORY:JOINT:ARG4:4:ARG3:1]
[BP_LAYERS:BY_CATEGORY:SPINE:NERVE:2:ARG4:2]
[BP_LAYERS:BY_CATEGORY:BRAIN:BRAIN:100]
[BP_LAYERS:BY_CATEGORY:HORN:ARG4:2:HORN:2]
[BP_LAYERS:BY_CATEGORY:FINGER:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:TOE:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:FIN:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:FLIPPER:ARG4:25:ARG3:25:ARG1:1]
[BP_LAYERS:BY_CATEGORY:HUMP:ARG2:50:ARG1:1]
[BP_LAYERS:BY_CATEGORY:LIP:ARG3:10:ARG1:1]
[BP_LAYERS:BY_CATEGORY:TONGUE:ARG3:10:ARG1:1]
[BP_LAYERS:BY_CATEGORY:CHEEK:ARG1:100]
[BP_LAYERS:BY_CATEGORY:EYELID:ARG1:100]
[BP_LAYERS:BY_CATEGORY:THROAT:ARG1:100]
[BP_LAYERS:BY_CATEGORY:HOOF:HOOF:100]
[BP_LAYERS:BY_CATEGORY:HOOF_FRONT:HOOF:100]
[BP_LAYERS:BY_CATEGORY:HOOF_REAR:HOOF:100]
[BP_LAYERS:BY_CATEGORY:SKULL:ARG4:100]
(You can adjust the thicknesses as needed, maybe by adding an extra 5 to all the ARG3 tokens.
Then put this in your creature definition:
[BODY_DETAIL_PLAN:PINKY_TISSUE_LAYERS:SKIN:FAT:MUSCLE:BONE:CARTILAGE]
I know there's FAT in there, but it's not actually used anywhere in the body plan. it's just there to make sure all the references are correct.