Thanks for the positive feedback Chris. It only really started as my Tommy was missing the complete assembly (but had the servo controller board) I could not stand playing the game knowing that such a vital feature was not working. As an electronics and software engineer I sometime dabble with mechanical engineering I thought that I could teach myself a bit of 3D CAD and find a solution. After a couple of prototypes and a lot of testing I have a sound solution. Believe me that there is a lot, lot more to them than a couple of bits of plastic; they have central hub, ribbing, strengthening, bearing surfaces, spring locators, etc. If I could have knocked a set up from cardboard and sticky backed plastic I certainly would have done and saved myself a lot of time. The original plan was to make one set for me; the selling only came later when I saw that there was a small, but interesting demand for them.
Whilst the printing is still quite expensive as the parts are relatively large and need to be quite accurate for where they turn on the spindle, and there is the cost of the servo and spring, the €152 leaves me a little bit for my troubles, but more importantly, they bring another Tommy back to be the game that it was always meant to be - I could not imagine my game without them now.