On a Mac press Cmd-Shift-4 then draw a rectangle around what you want to capture and release the mouse.
Instead of going to your clipboard, the screenshot is saved to your desktop with the date and time appended.
You could try the following:
1. reduce the size of the image
2. add a colour cast (e.g. sepia) to make it look different
3. acknowledge the website where you got it from (if 'Contact us' has failed)
With decent auction houses, e.g. Noonans, the online bid window shows not only the current bid but also what that equals in terms of hammer, so you don't have to do any mental arithmetic while bidding.
Interestingly if you look at my farthing you can see that the 6 has been rotated resulting in 2 tails. However you will also note that the 1 needs the same treatment, and the 2 is - as so often with the final digit - badly positioned. You can understand the correction of the 6 as it was needed for more than one year, but by that token you would think the 1 should have been corrected as it was the millennium digit!
Yes, if you reduce the f ile size you shouldn't have any difficulty - there's plenty of software out there which will not only make the image smaller, but also reduce its quality to a still acceptable image.