1 Therefore, I have question number 1. How do I "reattach" this, once the dying process is finished. Can I use a screw back concho and screw it through the leather and into the tree? Or do I use some sort of nail/tack, and then cover it with new rosettes and conchos? If the latter, what sort of nail/tack do I use?
You can use a screw back concho if want or put a regular screw in with a finish washer. For the conchos use a nail to put the bottom one on then do a bleed to hold the top one on.
2 Next, the saddle seat has very pretty stitching, but some of the stitching is coming undone. I'd like to refinish the seat, and then restitch it. I'm assuming doing it in this order will prevent the dye from staining the thread . Or, (question 2) will waxed thread repel the dye? Question 3: since the holes are already made, do I need to use a stitching awl, or can I just use a leather sewing needle?
If the sticihing that is loose is in the seat i would just leave it alone. Unless you plan on putting a new seat in. Waxed tread will not stop dye or i never have found it to.
Stiching along side the seat you need to sew with two needles. If your lucky you can hold the seat up high enough to sew after you take the screws and nails out of both sides. If you want to take the whole seat out it is probley glued and may have some nails along the filler of the cheyenne roll. I would leave that alone for now.
Good luck.