You could take a washable marker and a ruler or sheet of paper and line it up with the coin and make a mark at the top and bottom of the case. Then turn the case over and align the ruler up with the marks and see how the coins alignment is. Washable marker can then be wiped off leaving no trace.
Like this..sorry for the bad focus..just did it quick for an example.

Like this..sorry for the bad focus..just did it quick for an example.





















