I appreciate the advice & comments on the action. To be honest I hadn't even considered picking up a suitable metford barrel...I don't know why I didn't think of that. Chances for finding something here in NZ would be very unlikely but you never know. Are there any particular sources, companies or auction sites in the worth checking out for something like this?
I talked to a very well versed gunsmith (EX Purdeys)about the action today. Like you he said don't change a thing, use it as is.
Looks like I'm on the look out for a barrel. I'll have to keep my eyes peeled.
Thanks anyway & do please let me know if you stumble or know of a suitable barrel in your travel.