Putting this here…
We use Steve Smethurst in Salford to refurb alloy parts…the finish is exceptional in my view…not cheap…but not daft either…
WOW! 
Looks like new. will you seal that finish with lacquer? would be a shame to let it tarnish.
No…its quite durable…the media 'peens’the alloy…
So no further cost involved in the finish, Thumb’s up from me 
Drool! 