Tim S wrote:

SWMBO has requested said pipe for a few areas which will be on show (I'd be
happy to polish and lacquer the copper but there you go).

Mrs F. expressed disdain at the thought of having polished copper on
show. So we had to use something shiny.

It was going to be chromed copper, but stainless worked out cheaper and
less likely to have problems - I've seen chrome peel and pit in some
areas of use, notably outside which was one place (the gardener's loo)
where she wanted chrome tube used.

Which would be the most advised method for jointing?

File the chrome off and solder or compression?

Compression, attempting to solder will just look vile.