i too have looked around for any Lyons Tours old archive but nothing really comes up...
our first holiday to Costa Brava at Malgrat in 1964 was with Everyman (part of Lunn Poly) and we flew British Eagle Britannia jet-prop to Barcelona
my dad would not go with Lyons as they used OLD planes and flew to Perpignan!
(which is were we came in lol )
sometimes Ebay brings up old holiday brochures...cannot find any ref to hotel Acapulco in calella but only one hotel called that in Lloret de mar...
i ended up working with another old long gone tour company called Swan Tours (not swan hellenic) who in 1975 were bought out by Inghams.
BTW you say you flew in 1966 to BCN as you mention...Lyons still coached some of their holidaymakers across the border from France to the Costa Brava...