RE: Glossy neck.
I’ve found after a couple of coats of anything (well, Tru Oil, gloss poly and satin poly) it starts to gloss up.
I had many many layers of Tru Oil on a guitar neck that I could not stand the feel of (before or after polishing).
I took to the back of the neck with steel wool and I was happy enough with the end result.
I’d recommend steel wool on the back of the neck, then polish the back of the headstock and heel. That way you get a smooth transition rather than a slightly scratchy edge where you ended with the steel wool.
Edit: make sure you have plenty of layers of Tru Oil first. You don’t want to cut back to wood. That would make you unhappy.