Chris Bacon wrote:

So: "Because "stranded" aluminium wiring wasn't used in
situations like the OP mentions, or in such small sizes,

I think you'll find it was used for small sizes for a while, from the
late 60s to early 70s. Aluminium twin & earth appeared when the price
of copper shot up and its use ended when it was 'banned', having caused
a lot of trouble.

Aluminium is still allowed in house wiring, but only for sizes of 16
mm^2 and above.

and it wasn't used in the early '80s". That's about it, really.

Yes, the small sizes had gone by then.

--
Andy