again, good to hear on progress andrew.
re hinges, i use the du-bro round barbed ones on the ask 13 and 18. they look quite realistic and work well. my 13 is 21 years old this year and i had no problems with the canopy until i hit it with my boot and split the plastic right at the hinge points.
i use spring loaded hatch catches to keep the canopies closed.
the canopy on the asw 20 is held on by a tight fitting piece of fibre glass strip at the back which engages in the top of the fuse and again a spring loaded hatch catch at the front.
i used small strong magnets (neodymium i think they're called)on a hatch on my ka3 and they stay well stuck in place.