The success of Operation Mincemeat caused the Germans to disregard later genuine document finds. Examples include:
Two days after the D-Day landings, the Germans discovered an abandoned landing craft washed up on the Vire estuary in Normandy, containing top secret documents detailing future military targets in the region. Hitler, believing this was a deception similar to Operation Mincemeat, ignored the documents, having already been convinced by numerous deceptions that the main invasion was still to come through the Pas de Calais.
During Operation Market-Garden, the drive into the Netherlands in September 1944, a complete operations order with maps and graphics for the airborne phase of the invasion, which was not supposed to be brought with the invading troops, was inadvertently left behind on a transport glider. The operations order fell into German hands, but the Germans, convinced that this was another attempt at Mincemeat-style deception, actually deployed their forces contrary to the information before them.
Но вообще история потрясающая - создать кучу подлинных писем и счетов в карманах вымышленного майора, подкинутого трупом к испанскому берегу, чтобы через испанцев показать немцам несколько обманных писем. Только уж как то слишком книжно.