Originally Posted By Dab of oppo
A dip stick might be a better option!

And traditional too, I don't know if later F types had a gauge but no twins ever did. I've got a lovely stick with notches cut in it at 1/2 gallon, 1 gallon, 2 gallons, and 3 gallons (capacity is 3.5 gallons).

1930 Super Sports Aero 'The Elk'