My late machinist (an ex Jaguar cars toolmaker) who sadly died in 2005, was a savant. I never found anything he could not make. He produced three perfect copies of the TP rings, & made quite a few of the bases, sufficient that I had enough to sell commercially, at least for a while. However, he was prepared to do this as he had dropped out of mainstream working life, & was happy to produce things for well below the going rate. He loved the challenge, was very interested in the history, & just wanted to make enough money to keep food in his belly, the mortgage paid, & a little fritter money. And luckily he was capable of making most of the tooling he required himself. All of these mounts can be made but they may not be made because of the costs. Most of the stuff that I've been selling over the years simply would not have materialised if I hadn't had the late Graham Smith to make it all happen.