Marianne de Dulac

Are there any Marianne specialists in the room? I really do hope so because I've come across a puzzlement which I'd like to have solved!

It concerns the Marianne de Dulac series from France, issued in 1944/1945, also known as Marianne de Londres, because the stamps were printed by De La Rue in London. Now, De La Rue is famously impossible when it comes to attributing their stamp work to certain engravers. That's probably why Stanley Gibbons does not mention any engraver(s) for these stamps, but luckily, the splendid French website Phil-Ouest does. But there's a snag.

For the majority of the series, or even more precisely, for all but one stamp, the website states that the die was engraved by both the designer, Edmond Dulac, and a second engraver, Leonard Vincent Phillips.

Nor worries yet, but the very first stamp from this set, and the only one issued in 1944 (the remainder being issued in 1945), is only engraved by said Mr Phillips, with Dulac only getting a credit for the design. This concerns the 1f50 rose.

Now I've had several close looks, and you can see copies of both the 1944 and 1945 stamps here in this post, but for the life of me I can't see any differences in the engravings.

So what's going on here? Is the information correct? If so, this would imply two dies, or at least a retouched die or something. So shouldn't there then be noticeable differences? Can you actually see any? By the way, clicking on the images will enlarge them for you to have a better look!

I've also asked Phil-Ouest for clarification if they can give any, but if any of you, my dear readers, know, then please let me know!