Your idea should work but you will probably meet lots of problems. I wouldn't try it on anything other than a small machine.
The rolled strip will be perfectly satisfactory magnetically but there is a large force trying to pull the whole thing out of the groove in the plywood. I have never found superglue capable of anything, good epoxy may do it. You would be safer to gut the groove on the front surface and make holes for the magnets to go through from the back . It would not be as easy but more certain to hold.
There is still the question of strength of the plywood discs and you would need to be careful to take the prop forces directly to the hub.
In the end you would be far better off buying a couple of steel discs if you don't have the facilities to cut your own.
For a machine under 6ft I think the composite plywood steel construction would work in a dry climate ( wouldn't last long here).
Flux