I can't see the point of the adjustable ones for road use. A Morgan's suspension and chassis design is extremely limited and the ideal camber degree settings are well known.

For racing, that's another matter but even on slicks (real slicks, not road legal rubber) I'm unsure that anyone would go beyond 1.25 degrees as it's rear wheel lift caused by unequal roll centres that is the main limitation. Non adjustable camber plates are quite easy to change and the benefit of adjustable, unless one is overcoming a bent chassis, does not overcome the need to re-adjust the toe-in.