Orange Tree Advice Request

Gday,
I’m in Western Australia and this year is my first looking after 2 established Orange tree’s.

The first 6 photos are of a Washington Naval- the Orange (well Green-Orange lol) is what first caught my eye with strange black marks on lower side and the next photo is the top side – which helped me notice that many of the leaves in that area appear blackened. The rest of these tree as far as I’ve seen seems ok and after all the rain Perth has recently had these are the biggest Washington Navel’s can remember on this tree -my dear old mum’s house.

The 6th photo shows a close up of what looks like to me to be new pee sized oranges perhaps, but I don’t recall ever remembering her trees to fruit like that?

The last 3 photos are of a massive Seville, which I can remember being ‘Big’ when she moved in 35yrs ago – the neighbour 2 doors down thinks that this tree is 50+yrs old. The fruit photo shows it’s kind of dried and faded on its top side mostly- it’s right on the fence line above the next door neighbour’s swimming pool – which I assume is most likely the result cause of this fruit.

Everything else appears ok I think, this tree does have a big issue with massive thorn spikes on most of its branches, which makes it very hard to climb to pick fruit which would be preferable all the fruit dropping from so high always splits. Can anything be done about the thorns? What would happen if the horns were cut back/off where it comes off the branch?

A side topic also is, apart from marmalade, what to do with so many oranges once they start to drop? I’ve made Orangecello a few years back with Blood Oranges which worked out great but that only needs so much zest? So any more hints, tips or advice would be really appreciated- thanks & cheers for now., 🍻🙏🏼🍊