No-one really cared 10 or 12 years ago when it was proposed (and implemented) by an OC Eng at St Mawgan (except for OC Eng). As ToTD mentioned not all cabs had the tail letter applied. And some that have had them re-applied recently (as they go thru Valley) have been done in rather a grand font... certainly not the font required/as defined by the aircraft repair manual... so, does that make it an illegal modification?
As for the "Sea King" markings... well there's an old story that it was an oversight or random caption on an original plan and that it was never intended to be on the airframe itself but subsequently became part of the aircraft markings anyway for the past umpty-ump years. However that may well just be an urban myth.
