Thanks for the input gentlemen.
The dealer took it to a local gunsmith to get it valued with a view to me making an offer.
He dated it but I don't know how or by what marks. I could not see any dates or crowns stamped anywhere obvious.
I have seen the one similar on guntrader but it does not look in as good condition and as you say has been there for months which seems to indicate little interest.
I have also gone through "Joe salter's" site among many others and don't remember seeing one the same. I will have another look.
There is also one similar on "Charles Stuart and Associates" site but not with the original sights still in place.
The 'perchbelly stock' could be from spares or an ealrier rifle I suppose as it's a Fulton hibrid.
So frustrating that it's now out of reach , locked in a cupboard. I could be shooting it today, or taking it apart to see what it's made of!.

Thanks again for the interest. If I get another look I'll let you know.