Nice work, I have been looking at turtles for a few years.
One of these days.
second attempt? impressed.
I reckon one piece, I have found the the welds stretch nicely when belted after they have cooled.
I did one years ago out of stainless steel as a gift for a friend. It was large, I dished out shell on pels machine, then ran an edge all round using a hand jenny.
After this, marked out segments, then dished further using leather beanbag and ball end of ball pein hammer, then got various colour contrast with O&A flame.
I did have pictures, gone when an old pc terminally crashed!!