Hi Hornet, how did you get on with those eggs mate? I have a similar dilemma, eggs that look suspect from the outside, when candled I can see veins but only a small mass inside them, when they should be almost full term, Im not too confident. One went bad only a week into incubation, wouldnt candle and stank real bad with some funky fungus and shell looking wet in parts and oozing some yellowish stuff from the bottom of the egg, and it was affecting other eggs so I removed it and dissected it, and man did it stink when I cut it open! I knew it would but had to see inside, found the tinyest little beginnings of a snake in there.
Good luck with the eggs, if you have figured it out, please share via pm