As far as I know that guy on Ebay also offers to make necks from African Mahogany, which is what BaCH used for the BaCHbird necks.
He built me one.
Needed a maho neck for an EB3 project bought off eBay (seller claimed it had ´the typical´headstock repair, turned out to be a cut down maple bolt on neck - long scale! ..with the original fretboard glued on top).
Neck was african mahogany, impressed with both how it sounded (can´t tell a difference) and fitted (almost no modification/sanding needed on the heel before glueing)
So at least for me, he seems to know gibson necks well. All i had to do was shape headstock, inlay it, mount trussrod, glue down trussrodstrip, glue on fingerboard, and paint. Easy fix, as they say