No, and 7 psi is not even 0.5 bar. But I wonder how Ed put the nipple into the underside of the shaft housing and how he got the left-hand crankshaft. On the Veco 45, there is no such swelling in the cast part like on my OS 19. I think Ed did it himself in his machine shop, and for him it was easier to make a new crankshaft than a left-hand propeller. Did you read the paragraph about Ed making Nylon parts in the interview I posted the link to?

BTW, I wonder if the ribs in the baby bottle were really able to stand the pressure. Why not simply a round bottle, or even a bubble tank?