Hi Bill. I have looked my database and found 3 styles.
The first style was used up to around YG2S4 1950 and the bracket used was this type.
Attachment:
Starter solenoid - pre 2000.jpg
There was a bracket change which was fitted to cars from around the YG2S4 1950 to YG2S4 2800 and this changed the angle of the solenoid. Its hard to get an exact change point because there are not many unmolested cars still getting around. This change point might have been by engine number but I haven't gone that deep into it.
Attachment:
Starter solenoid 2000 - 2800.jpg
The last style had its bracket bolted under the top engine steady like the clubman/leyland mini which raised the solenoid to give room for the washer bottle. This was on the flappy handle cars from the early YG2S4 2800s.
Attachment:
Starter solenoid post 2800.jpg
Here are a few of the cars I have used to work out the change point from photos I have. Some of these have been restored and the owners might have changed the brackets over.
First style
1485, 1514, 1590, 1540, 1576, 1598, 1654, 1659, 1663, 1675, 1681, 1685, 1707, 1710, 1734, 1732, 1738, 1749, 1757, 1762, 1766, 1790, 1792, 1814, 1851, 1857, 1866, 1929, 1946,
Second style
1853, 1956, 1974, 1991, 2031, 2036, 2058, 2064, 2072, 2083, 2164, 2225, 2260, 2262, 2286, 2295, 2311, 2341, 2352, 2360, 2362, 2375, 2393, 2423, 2435, 2449, 2462, 2499, 2501, 2506, 2524, 2554, 2593, 2598, 2644, 2653, 2662, 2762, 2700, 2797, 2891,
Third style
2821, 2851, 2855, 2859, 2869, 2871, 2876, 2883,