Mark's comment is correct.
The Roy Child gouge is the HS1 aka Superflute which is a 5/8" gouge.
A search on the Henry Taylor website (Click on Gouges in the side bar menu) gives:
The original Superflute HS1, designed in 1978 by Roy Child, has sold in thousands all over the world and remains the ultimate gouge used by most leading turners. Now made in a range of sizes the ½" or 3/8" gouge recommended for general purpose work and the ¼ gouge for small bowls on very delicate cuts.
Another search on the Henry Taylor website (click on H.S.S. Woodturning Tools - Page 1 in the side bar menu)) shows HS67 as a 11/4" x 3/8" bowl scraper under the Richard Raffan design.