I would suggest that manufacturing has changed over the years to use less material for the same clamping effort.
I remember Jubilee being the premier brand in the UK years ago. Perhaps a google search in the UK might yield something or a post on
www.hmvf.co.uk would put you in touch with those in the know in the UK.
There is a bible kept in our shop and that is the Spaenaur catalogue.
I think you will be lucky to find them like that nowadays.
Here is the company nowadays, perhaps an email with pictures to them?
http://www.jubileeclips.co.uk/
Will those ones clean up and be reusable or are they shot?
Robin