Diemai- Sometimes I think you must live next door to me. About three weeks back I bought the same hinges (aeroplane flaps), but they are nylon/plastic. They have been sitting on the bench since, and every now and then I pick them up and play with them - they also have a drawbacks, the pin is a bit too tight, and I'm not sure I want to muck around inserting a narrower pin, also doubt weather these would hold up in cold water which would make the plastic more brittle.
I like your determination, and work with these brass ones, and looks like it will work, size is always a problem, and I am still mucking around with the DNA hinges, which have a myriad of small problems, but am getting there.
Keep up the good work and keep us posted on how they work.pete