Here is a comment from 'across the pond!'
Now in my mid 70's and with a friend who is in his 80's who came back to playing in his 70's and now plays in 3 community orchestras. I am a retired pro but now just help out locally whilst learning the flute (yes, the 'dark side!).
I can, without any hesitation, (and my friend agrees) that the KEY to all your future enjoyment of playing is to nail that Arban, Why? well, as I always hammered it into my young pupils - you will find in practically every piece of music, a passage that is a group of notes you will have learned in the Arban. This could be a run of notes that is part of a scale, dominant 7th, chromatic scale etc. The Arban study patterns that are imprinted on your brain will transfer them to your fingers automatically.
You only have to learn a scale once to use that skill for the rest of your playing life. I am using the same philosophy in learning the flute - it's a chore, boring, frustrating etc but it has enabled me to join and enjoy music with two flute choirs after only 6 months, so well-worth the effort.