Thanks for your thoughts. We might sell 500 in a year and hand assembly is fine given that quantity. Would like to discover a method that yields zero defects. For environmental reasons, would rather not use lead solder. Using a 3D printer sounds interesting. Would have to invest in one and then do a lot of learning, experimenting, but might be worth considering, so thanks for the idea.
Are you using lead solder? Any particular reflow oven?