A place to gather windshield wiper issues.

From Joel's (the builder of Glassics and Replicars)  recollection in 2006:

Wipers were from a Scout 800A that mounted on the top of the windshield.  When we went to the Ford (V-8) it didn't have a double action fuel pump, so when you stepped on the gas the wipers stopped, so we started adding a vacuum tank (the tank was a Ford item)  ..about a quart in size to give the extra source while under (short) acceleration - then just let up for an instant and the tank re-loaded for another (short) acceleration  Glassics had the vacuum wipers throughout all production, as I recall...... 

Then (beginning with Replicars in 1976) we went to the Lucas and the rest is history...

1978 Wiper assembly.

1978 Phaeton. My windshield wipers came to rest
 at the wrong end of the cycle. They were not
 flat against the cowl, they were pretty much upright. 

Joel says that this was made by Lucas for various British cars. The metal plate (hard to see when in the car -- see the third picture) has the marks as follows

a circle with a Y in it, or a three legged steering wheel - and the numbers 75664F also 14 W and 12 V also 12 78

Removing wiper motor and gear assembly - first, disconnect wires and pull out electric box.
The pokey thing on the yellow electric connector is a switch. When power is turned off to the wipers, they continue to run until a bump on the gear inside pushes that pin up into the box and shuts off the power.
The brass clip holds the box in place. To remove the box, pull it toward you and up.

The brass colored cap holds the cable into the end of the unit. That needs to be unscrewed so that you have some play to remove the assembly and the holding bracket from the firewall. You will need to flip the unit over to get to the back side of the gear box.

These are the wire numbers for the wires going into the wiper switch. I could not see any markings on my wires, but I noticed that # 57 looks purple on my car. Joel said that originally the numbers were on the wire connector ends.

4 bolts held on the bracket that held the motor and gear assembly. The circle shows where I pulled on the cable to get room to flip the unit over .I next removed the back plate. The two hex head screws inside the circle are still attached. the two on the right side I have already removed.

Finally you can remove the motor and gears from t he car. #1 is the plastic gear. On the back of that round gear is a bump that pushes the switch to shut off (park) the wipers at the right spot. #2 is the pin that the arm slips over. It reminds me of the front wheel of a locomotive. To the left of #3 is the worm gear from the motor. It spins around and connects to the plastic gear.

In MY case, the metal plate on top of the plastic gear was installed backwards (see the two square notches?) I lifted the metal plate off of the plastic gear and rotated it 180 degrees. Go back to the first picture and you will see the other end of that metal plate as the shaft end in the upper right corner. It also had a c shaped washer to hold it in place. The metal part was on a rod that went through to the other side -- the retaining clip had to be removed so I could lift up the metal enough to clear the two alignment bumps on the plastic gear enough to rotate it.

I probably have the ONLY car with that goofy problem.

ADJUSTMENT: The windshield wiper arms are push-on. I removed the arms, turned the wipers off, so that the round peg that the arms sit on went to their "park" position, then I merely put the arms on so that they would be just above the frame of the windshield bottom.