Westley may used the invisible type rifling untill the H&H patent ran out in 1906, but they changed after that. The invisible rifling guns could not throw shot worth a dam. There were variations between Paradox and Explora ratchet rifling as well. One is more shallow than the other.
Good luck building the barrels. I would be interested to know how they came out. I do have the Fosberry patent info, but Holland deviated some from this.
JZ