I agree 100% on date, and on the "bit of a mish-mash".

And chevrons are later too.
And the very dark amethyst is indicative of early '70s, it matches the cubes and lollipops (and that small cylinder I made you look at, at the Fair last November, John.)
Phoenician made small everted rim dishes with both chevrons and bubbly stripes, some of which might have been mistaken for Mdina, if unmarked.
I don't, for one second, think this one here is Phoenician - it's far too different.
The nearest to crystal blue stripe on ochre would be the Onion stripey design, but that was made using silver nitrate, not chloride. Crystal blue stripe was one of the earliest ranges to be put into production and is still going.
I'd still think this dish would be earlier than any with the chevron pattern, so I'd be leaning towards the early '70s rather than around the middle.
It also looks quite big.

What is the diameter, Marc?