Guest, did say that Hank Marvin stuck with one sound.. this is actually not quite true. Though we have the stereotype signature sound of the Shadows.. they actually introduced one of the first acoustic guitar pieces of its type into the high ends of the UK charts with the simple, but effective 'Guitar Tango'.. and also later used various guitar effects with less success, before moving back into the more MOR market with covers using the old sound.   This is Cliff playing Apache live with three of the Shadows in a spoof... (slightly nervously, with stumbles and dropped notes)

https://www.youtube.com/watch?v=PbYXqPIqHsE