Hey Midget98,
You are spot on the money with all of that. From the nobby tyres to the hit and miss governor. This is fitted to the 25C 2 cycle engines as well but I did think the 11C engine was the earlier model so that was interesting to see your edit.
In all, there's about 20 attachments, I totally think I'm going to have to make one of the cart things with wheels

I picked mine up on Wednesday, should run but hasn't done so for a while. Will start with new tyres, a good wash/grease/oil and a bit of love under the covers and see if we cant sark some life into the old girl.