I have "the first gem in my collection" which I stumbled up on when I was a teenager, a Calderwood shotgun, early irish made gun. James Calderwood advertised as gunmaker to the lord lieutenant in Ireland, and most examples I have seen have been truly stunning guns finished to a high standard. I feel like Calderwood as a maker has been overlooked in the annals of gunmaking history its not a name we have all heard of like rigby's or even Kavanagh.
I found an old book on google where Calderwood was credited along side makers we know like Manton for pushing the trade forwards to making what we recognise as truly fine sporting guns - I have since lost this reference but I'm sure ill have it somewhere.