At the end, I'm not producing my own design. There is not added value if SRP also did Iit, and with an exact copy (mine was internally differences and had risks of mistakes in a new product). I have 5 or 6 stems that need it, so I reached an agreement with Jeff from SRP to buy a bunch and use them and also sell them to friends and retrobike passionates. This way I got a nice price per unit and he sells a nice batch. I'm going to sell them at 15€ + shipping. I think I can send it in a letter if you agree not insured. I need to check costs. We can discuss prices for more than 2 units.
Maybe I'm having only 15 units.