Hi Jhs,
From my standpoint:
(1) J has no reason to incarnate via the slow gestation and birth method as he is free of such processes, though I suppose he could do it if he wished to manifest in this way. However, I see no reason why his manifestation (physical or otherwise) would require this.
(2) If J does choose to manifest in this way, I suppose he may have birthmarks marking his wounds (as he retained the actual wounds in his post-resurrection appearances). However, that would also be up to him. As previously noted, he can manifest as he chooses. In various reports of appearances and visions he usually continues to bear these wounds (but compare his post-resurrection appearance as the "Ancient of Days" in the first part of the Book of Revelations, or his appearance as the "Lamb" that was slain a bit further on!). He can manifest as he chooses, and appears to manifest in a manner that will best convey his message.
From the foregoing, I would say your proposition is possible, but by no means necessary or inevitable.
Cordially,
S&S