Courgette hiccough

Not sure what do be ailing a couple of my courgettes - pictures attached.  One of them had about 2/3 of the leaves brown, dry and brittle, although the leaf stems remained green and 'normal' - is this likely to be sun scorching or something - it happened in the space of about 36 hours.  The fruits on the plant seem to be staying small and loafing around, watching TV, phoning out for pizzas, that sort of thing, simply not pulling their weight.

The others are all showing grey spots to one degree or another as per the other picture, although the fruiting appears thus far to be unaffected - is it safe to ignore?    WHatever it is has hit them separately - they are scattered widely around the garden, no two nearer than about fifteen feet apart.

For both sets, the dried up papyrus and the plooky spots, is it still normally OK to compost them or would the general advice be to play safe and burn 'em?

Probably concerned over nothing but it would be nice to know one way or t'other and this is  definitely the right place to ask!

The grey patches are normal markings but if it looks like mould patches its whitemould. Mine got it after all the very wet weather last wek. I've cut the affected leaves of but read it can be treated with 1 part milk 4 part water spray