That a Showa power trim unit and sleeves are friction fitted. I have never seen the sleeves for sale.This trim is also used on Yammy, Suzuki,Honda Tohatsu Nissian motors
Your really under powered on a 23' so a prop like below is best.
https://bblades.com/shop/propellers/brand/turbo/turbo-pontoon-1/
https://propcomarinepropellers.com/collections/houseboat-workboat-barge-pontoon-boat-propellers