Here’s a quick little function you can use in the command bar that iterates through the parts in workspace, and selects its touching parts that have the same Position, Orientation, and Size.
function selectDoubles()
local checked = {}
local doubles = {}
for _, part in next, workspace:GetDescendants() do
if part:IsA('BasePart') and part ~= workspace.Terrain then
if checked[part] == nil then
local transmitter = part.Touched:Connect(function() end)
for _, touch in next, part:GetTouchingParts() do
if touch.Position == part.Position and touch.Orientation == part.Orientation and touch.Size == part.Size then
checked[touch] = not nil
table.insert(doubles, touch)
end
end
transmitter:Disconnect()
end
end
end
print('Selected', #doubles, ' duplicate parts')
game.Selection:Set(doubles)
end