"I would also add, that if the bolt is
Australian
, it may have been changed out in service...in other words, it is the right bolt."
No.
A replacement bolt fitted inside the D^D system would be, at the very least, lined out and renumbered to match the receiver. More likely, it would simply have a matching number but lack the assembly number that indicates an original bolt.
As an example: I found an "A" series Lithgow bolt and stuck it in my mismatched 1920, but as much as I would like to kid myself, it's not the
right bolt.
As for what this '27 might be worth in the US---I just paid $400US for a nearly perfect
Brazilian
Contract M1908 Mauser----would I trade it for two mismatched 1927 Lithgows with bad bores?
The answer is not merely "NO" but "Fill-in-the-blank NO".
-----krinko