I bought the plastic lid almost by accident having decided against it, “definitely this time & no arguing or rethinks”.
“Yes dear”.
It didn’t stop me from putting a really really really cheeky bit on one in the north east.
We were on holiday when it transpired that I was the most generous, in fact the only generous person.
Explain that at breakfast. I’ve had worse days.
In the preceding years I’ve seen hard tops stored from the frankly reckless through to the ultra cosseted, the chunks missing or broken around the periphery tell stories of there own. But I doubt there was one which has suffered enough not to fit & after the proscribed farting about time, seal.
The way you envisage it as described is the way I would approach it, keeping the whole assembly in shear; find the point of balance across the quarter panels & use those as your anchors.
How you affix the anchors is entirely up to you, but you could do a lot worse than machine screw eyes into blind nuts with a reasonable plate to spread the load. I would guess the stress loading would be better this way than that on my system, where the loading is plane to the surface, granted with four fixing points.
It’s then just a couple of cords from the eyes up to wood screw eyes into the roof timbers.
M