I would cut out the bald spots and sew them,as long as they are small.Still a good pelt with lots of useable fur.
Hair slipping in the armpit area is often from folded skin not drying.
If there is large areas of hairslip dont waste your time trying to cut and sew it.
And the Auctions recommend leaving those legs in the pelt so they don't tear them. I see FHA is recommending pinning out front legs prior to turning pelt and leaving them inside. Must be having issues related to the earlier recommendation?
Dont understnd you question Dirt.Front legskins when left on, are dried along with the pelt when the pelt is on the board fur in.When the pelt is turned fur out the dry legskins can be left inside,except on complete skins where certain buyers want to inspect the handling of the feet.In those cases the front legskins are turned to be outside the pelt when the pelt is turned fur out.
The problem with hairlip associated with legskins/armpits is in the initial drying of the skin when fur in.It is caused by folds when skins are dried in the vertical position as opposed to drying horizontal which will prevent that issue.
I leave all legskins long on canines and cats. I make extra money with them.