26 were rebuilt by George Whale from Class B 4-cylinder compounds with the simple addition of a leading pony truck to reduce excessive front overhang between 1904 and 1908.

The only alteration was to wheelbase and weight, but when the letter classification system was introduced in 1911, this took them into a different class.

12 had been modified by the grouping of 1923, and a further pair were rebuilt in January and February of that year.

Of the remaining ten Class Es, the LMS allocated them the numbers 9600-9.

LMS numbers in parentheses were not carried prior to rebuilding as G1 or withdrawal.