Just keep him extra clean. The swolleness may be a sign of beginning infection. That poor baby.
I would still have him checked.
I don't think he's a leatherback though. He has nodules on his back and when my little leather were that little they were very smooth. While you can have varying degrees of lb, His back is just too bumpy.
For an example heres one of my normal backs at that size compared to an lb.
Normal back
Lb
You can see on especially the sides where the stripes are that lbs are quite smooth.
He's very pretty either way and I wish you the best with him.
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