Excellent display, congratulations to everyone involved. A very good mix of machinery and tools with a few rare and unusual items. The whole section really shows the range of items covered by the heading ‘horticultural’ and specifically what the VHGMC is all about.
I am sure if you send an e mail to Meetens with details of your engine and parts required they will be able to tell you if they are available and what the cost would be. If you have the engine number it will help. Another possibility is if this maodel of engine was used on motorcycles it could be worth looking at vintage motorcycle parts suppliers.
To find a donor engine you may need to buy an entire machine.
Plenty of information about fuel on the FBHVC website Another issue with modern fuel is the ethanol content and how it can degrade certain materials eg cork and rubber, also water accumalation.