Both UK& Aussie scopes were originally blued.
It'll make a lovely, but demanding, restoration project. Whilst the originals were blued might I suggest that it might not be the best option cosmetically, unless you have a modicum of skill with a Swissfile & are prepared to spend about 8 hours with the scope tube on your lap gently rocking the file over the pitting in order to lose most of it without leaving a visible flat on the tube? It drives me nuts (I have just suncorited a No32 Mk1 tube that was badly pitted until I spent 7 to 8 hours striking it up by hand, so as to preserve the markings & remove the minimum of metal. It also got bead blasted & parked before I painted it & it is now good to go). Bluing looks great so long as it is a perfectly smooth surface that is blued. It'll look terrible if you blue over pitting - in which case I would suncorite it. You can rub the suncorite down with fine wire wool & apply several progressive thin coats that do not look too dissimilar to bluing, so long as you get it right. It'll also tend to fill in some of the worst pitts.
Just my .02c. Good luck with the restoration, whichever way you decide to do it, & keep us posted!