Bonjour Tony,
Sorry for my French langage and thank you for Google traduction help
I hope this other video will help you to see how we use Teflon (PTFE) sheets for oscillating pistons:
I have seen again you video, these cylinders leaks seem definetely your main issue.
About lubricating, with Teflon, no more needed because you are right, your hull is quite narrow!
I can't wait to see this steam arrow on a pond (mine is currently also frozen).