ElleKitty which are you missing from the Royal Shield design?
Is it the 20 pence and 50 pence which make up part the design and a 1 pound with the full design?
The did not make any Royal Shield 50 pence coins for circulation in 2009, 2010, and 2011.
I have not seen a 2013 Royal Shield 50 pence. So not counting 2013, there have been 1,006,176,613 current size 50 pence coins made for circulation and the 2008 & 2012 Royal Shield 50 pence makes up 55,047,030 of those. So it can be a bit of a challenge to find a Royal Shield 50 pence some days. Now if you wanted a standard 1997 50 pence, that would be easy since they made 456,364,100 of those.
Ken