Updated: Jul 3, 2020
It has recently been discovered one of the Parts suppliers in the list above is now offering new ignition coils for the very early models. The vendor appears to have paid for new tooling and has produced a much-needed and previously unobtainable item.
You can see the item here: https://www.solex-motobecane.com/3-pieces-pour-velosolex/pieces-detachees-pour-velosolex-45cc-roues-de-600-vsx/bobine-dallumage-haute-tension-type-sev-pour-solex-45cc-330-660-1010-1400-500-5473.htm
Velosolex Club U.K. is not endorsing this product in any way, shape or form but merely bringing to the attention of members that a previously unobtainable and vital Solex part can now be purchased. Other vendors may be selling a similar part but we are currently unaware of anyone else.