Some or all of the info below may be of use to you
The '10 Calpin brothers in the King's Service' poster I /think/ was a special feature published in the Yorkshire Evening Press (The Press) who might have a better archived copy to send you if you were interested. We have a large mounted original copy of it at home and one day when I set a Calpin family history site up I'll put a hi-res version online. I'm Thomas, the great-grandchild of Thomas, the youngest of these 10 brothers.
There is quite a large 'Calpin contingency' in York, historically centred around the Walmgate area and I think a chap called Ray Calpin wrote a book a few years ago called 'History of the Calpin and Loftus families' - not sure if it's in print or if there are any copies flying around. This book contains a print of the 10 Calpin Brothers poster too if I remember right.
I'll post more when I get this site set up, hope that info is of any help