Replicating someone else’s layout in new edition

I wish Typophile had been revived a year ago when this came up for me, but the question is relevant again.

I’m doing e-book layout for a series the author is reissuing after rights reversion. Is it inappropriate for me to copy design decisions made by the first-edition typographer, like chapter-heading fonts and section-break fleurons? (With credit, of course; something like, “Typeset by Joel C. Salomon; original layout by Sam Designer”.) The first-edition designer was hired by the (now-defunct) publisher, not the author, if that matters?

How say you?

Reinterpretation Vs. Copying

Hello dear typophiles community,

A client asked me to use a font for his logo that he found on dafont (doh…)
The one is "Little Days" and supposed to be freeware.
However, reading its comments I've discovered it's extremely similar to this commercial font Memimas.

Looking forward, I've fallen on this article by Luc Devroye. He claims it’s not a copy, but I must admit I find his arguments totally wrong.