Step 1Place the pumpkin in a large nonreactive bowl, and toss with the salt, rubbing the salt evenly over all sides of the pumpkin pieces. Set the pumpkin aside for 3 to 4 hours to give the salt time to penetrate and soften the pieces. When the pumpkin is softened, carefully rinse off the pieces to remove all of the salt, and drain well.
Step 2In a large saucepan, combine the vinegar, water and sugar, loosely cover and bring to a boil. Reduce the heat slightly and add the pumpkin pieces. Return the heat to high, and as soon as the mixture comes to a simmer, remove from heat.
Step 3Ladle the pumpkin and hot vinegar mixture into a clean, nonreactive bowl, and stir in the garlic, thyme, sage, marjoram and peppercorns. Weight the pumpkin using a heavy plate so it stays submerged in the liquid.
Step 4Refrigerate the pumpkin for at least a day to give the flavors time to develop. The pickles will last, refrigerated, for up to 2 weeks.