These Gauges only fit the Type 4 and later '72 on Karmann Ghias.
These 'Stationary Petrol Heater' was only really an attractive option to new buyers in consistantly cold regions. Like Scandinavia, Rockies etc.
Lots of Canadian Campers have the additional petrol heaters for this reason.
I've had and sold several of these gauges over the years, but their appeal has only ever been limited. they are a less common sight these days at swapmeets.
It's a shame that these gauges don't fit beetles, because they are really cool looking..(anyone fancy trying to fit one??)
The 'Pre-Heating System' was very modern (remember this is the early 70's) and ahead of it's time. The additional cost for the new car buyer was resonably high in some markets and the option was never hugely popular.
The electrical system that controls this whole shabang certainly comes under the 'Black Arts' and nowadays is probably known only to Secret Societies and Freemasons