I am in the process of replacing the parachute band solution Porter uses. (I usually refer to it as “the Mickey Mouse” solution). Through the Internet I found this T-bar hatch fastener in the USA:
When I was at the International rally I bought four of them at Hamilton Marine in their Portland, Maine store. The people at the store ensured me there should be no problem sending parts to Europe. I have not put them on the boat yet so I can’t say how they work. I’ll report back after I mounted them on the hatch.
One of the reasons I waited with mounting is that I am considering using only two, together with two hinges similar, but much smaller, to this:
As you can see this hinge has a quick release pin that would still allow me to remove the hatch completely. I haven’t made up my mind yet.