Finally figured out how to assemble the remaining explosion sprites for late Sonic Crackers/Knuckles' Ringstar.
Thanks to these.
https://i.imgur.com/SWP7Kzm.png
https://i.imgur.com/SE1gl4I.png
No wonder I wasn't having luck before. 40 x 40, and flipped/mirrored.
=^-^=