This is a Vintage Frog 500 Spark Ignition engine from about 1950.
I just got it a couple of weeks ago from Australia and I don't think it's run in a long time. This is the very first time I have tried to start it as a full sparky.I ran it a couple of weeks ago with glow fuel and a glow plug and it ran well. Seems to run even better as a petrol engine!
The "condenser" is a WIMA MKS 4 0,1/250 capacitor which I bought from Maplins a while ago.
I have several other coils and condensers that I bought recently and I will be testing them in the near future.