So I ended up with a fixed carbon paddle with a used sup purchase. Paddle was too short for my liking.

I had an old 15cm section of scrap fixed cut off 29mm outer diameter. I just needed a joiner.

So I seperated an old adjustable paddle I had and then from the smaller shaft I cut off a 9cm section of 24mm outer diameter shaft to use as my joiner inside the OD 29mm ID 24mm scrap piece.

Removed handle on new paddle with heat gun.

Finally, I glued handle into scrap piece, scrap piece onto joiner, joiner into paddle shaft.