[The Australian Panther]

The penciling here is not Giacoia. Taking a good long look at it, I believe this is Mike Sekowsky penciling and inked by Giacoia. It's hard to tell, because there aren't many full-frames of characters, there are a lot of faces and closeups and Sekowsky's feet are his most idiosyncratic feature. So look at Page 4 last panel, Page 8 last panel, page 9 middle top panel, Page 20 (18 on the book) third panel, page 27 panel 3 (25 on the book) and look at the accentuated brow lines on many of the characters. Has to be Sekowsky.Second Artist I can't place, but not Franks pencils. Sy Barry perhaps? Cheers! If Giacoia had a Holmes strip in Newspapers, then Sekowsky was working on it with him.

Link to the book: Super Detective Library 078 - Sherlock Holmes and the Hound of the Baskervilles

I have a one-track mind. Just found this article which confirms that Sekowsky did a lot of ghosting.
https://www.tompstewart.com/blog/2015/10/8/so-what-kind-of-guy-was-mike-sekowsky
 

[Andrew999]

Very interesting - good research - thank you for posting this