Who are these people and what's the difference? Mystery Cache

The cache is not at the published co-ordinates, although these may help you work out the theme of the puzzle. Solve the picture clues to calculate the final co-ordinates to grab the cache. These will be within two miles of the published co-ordinates, a Geo-checker has been provided. You are looking for a magnetic camouflaged tubular container.

There are 8 picture clues to solve. Where any have multiple answers, please choose what will give you the larger difference number, even if this a two digit number. The information to derive the numbers is as understood at the start of November 2013. Once you have all 8, the cache can be found at:

N 51 (H-E)(F-A).(F-G)(B-H)(C*D)   W 000 (A-E)(B-D).(G+E)(B+C)(F-A)

You can check your answer on the Geo-checker provided.

Please be careful when retrieving the cache as it is close to a busy road and take special notice of the following warning:

AS WITH ALL CACHES PLACED IN AND AROUND CENTRAL LONDON, YOU ARE IN AN AREA THAT IS FREQUENTLY PATROLLED BY POLICE SO PLEASE DO NOT DRAW ATTENTION TO YOURSELF WITH SUSPICIOUS BEHAVIOUR AND IF YOU ARE APPROACHED, EXPLAIN ABOUT GEOCACHING.

If the above Geochecker is down, you can also check via this link on GeoChecker.com although there is no additional hint given on a correct answer.