I've written about the history of mezcal de pechuga in the state of Oaxaca dating to the 1930s (Articles by Alvin Starkman about mezcal - OAXACA MEZCAL & PULQUE (oaxaca-mezcal.com), and there is archival evidence from other parts of the country going back to the 1800s (The Passionate Foodie: An Expanded History of Pechuga Mezcal), but I have never come across a reference to lobster or other shellfish pechuga.