As with the WWII Navy MoH engravings, the cataloging stumbling block here is the dearth of photographs of officially engraved pieces. I have but six: Gurke, Walsh, Foss, Lucas, DeBlanc, and McCarthy. Gurke's is the only posthumous award and the photograph of that medal's engraving has been reproduced many times.
Based on this very narrow sampling I am able to identify but one format, with a couple of relatively minor variations:
THE PRESIDENT OF THE
(RANK AND NAME)
USMC (R if a reservist)
Of the six engraving photographs, three include the recipient's rank and name on a single line, and three put the rank on a separate line above the recipient's name. Gurke, Walsh, and Foss use one line for the information, while the pieces for Lucas, DeBlanc, and McCarthy put the rank (abbreviated) on a separate line. The medals for Gurke, Walsh, and Foss were all presented prior to 1945. The other three were 1945 and later.
The one tell-tale sign of an officially engraved USMC WWII MoH, is that they all apparently include the phrase "THE PRESIDENT OF THE/UNITED STATES/TO. The Marine Corps is the only service branch to ever include this information in its MoH engraving format. As I noted in my earlier post on USMC Korean War MoH engravings formats, this phrase was also used then, but "IN THE NAME OF THE CONGRESS" was added, in all but one sample.
On Gurke's medal, the word DECEASED is added to the line below USMC. I am going to assume that this notation was used on other WWII USMC posthumous awards.
On the line below USMC (or DECEASED) these pieces all contain the following (or some slight modification):
FOR HEROISM ABOVE AND BEYOND
THE CALL OF DUTY AGAINST
ENEMY JAPANESE FORCES ON (AT)
This phraseology is found on Gurke's piece. The inscription on Lucas's, DeBlanc's, and McCarthy's medals substitutes "GALLANTRY" for "HEROISM." Walsh's inscription reads "FOR EXTRAORDINARY HEROISM/AND INTREPIDITY/ABOVE AND BEYOND THE CALL/OF DUTY AGAINST ENEMY/...". The photo of Foss's engraving is of such poor quality I cannot be sure what phrase is used.
Here's Gurke's medal:
The tag on the lower arm is apparently an inventory number from the museum that holds this piece.
I do not have the date of presentation for this award. Gurke was KIA in November 1943, so I presume a presentation ceremony was held in 1944, possibly as late as 1945. If anyone has this information please consider posting it.
This is ace Ken Walsh's MoH engraving:
Walsh was presented his medal at the White House by FDR on February 8, 1944.
I would like to post Foss's engraving but the photo is just so bad its barely decipherable.