Here's another tip sent in by a visitor:

On 1/12/03, Rob Carleen of Pensacola, Florida, wrote:
>.... I had to go a bit further in that I replaced the leather seals. I did this by first grinding off the head of the copper rivet holding the brass washer to the piston and tapping out the old rivet. I bought a piece of scrap leather (about .070 thick) and cut out a 13/16 radius circle and punched a hole in the center. Using a coarse file, I shaved the leather down to about .050. I soaked it briefly in water and installed it, dressed side toward the piston, as this seemed to be the way the old one was installed, using a 6-40 screw and nut. I carefully (Bakelite is brittle) pushed the piston into the housing, a little at a time and rotating about 30 degrees each time, until it pushed all the way in. I left it like that for about four hours, removed the piston, (this took some patience, rocking and pulling) and left it out to dry overnight. I lubed the entire cup, both sides, with a liberal coating of dielectric grease and reassembled, ensuring that I had a good vacuum. The seal had shrunk slightly and I found that a single layer of trim tape under the leather cup edge improved the seal. I also file about 1/2 the thickness of the screw head off and sealed the screw to the brass washer.
>
>Just thought you'd like to know it was relatively simple to go the one step further.

On November 18, 2011, Jeremy B in Brisbane, AU, wrote:
"Had trouble with my turn signal switch". It had a combination of a seized piston, missing spring and broken adjustment screw mount. A new spring was fabricated out of a piece of an older spring, reshaped for a more tapered fit, piston cleaned and lubricated with silicone grease".

"The adjustment screw was replaced with a model aircraft mixture screw which was glued to the switch body. The screw works a treat and hasn't need adjusting since fitting. The hard part was figuring out what to use as the switch body was quite thin in that area once it was broken off. Not enough Bakelite to tap a new thread into".

Addendum October 9. 2021:
Here is an alternate switch that pops up occasionally. So far just a picture, not yet disassembled to see what's inside, and no word on a part number. MG TD, MG TF, and MGA all use the same vendor part number I don't know yet if one of these parts succeeds the other and may or may not have the same vendor part number (being interchangeable). There must be different Lucas part numbers, since the internal parts are different the assembly number must also be different.