UK Car Repair: 1959 RR SC 1, automatic transmission fluid, rubber grommet

Question
Can you tell me where the dipstick and fill is for the auto transmission on my 1959 RR SC 1.  What type fluid to use?

Answer
It is on the right side of the transmission tunnel and accessed by moving the carpet and underlay. The aperture is sealed with a rubber grommet. The dipstick will be found under the grommet, which is also where you will top it up with automatic transmission fluid, see the instructions on the dipstick and the car should be running and warm to top it up.  Make sure the handbrake is on.