I've only found two issues of these, so I'm not sure if there were any more for other units introduced at the time, such as the Met-Camm lightweights. They would quickly be replaced by the 33003 series instructions.
If you have any similar items not featured here, I would be pleased to hear from you.
Group 6
Covers the West Riding (Red Triangle) 125hp units.
Group 7
Covers the other 150hp (Yellow Diamond) units.
I'm guessing Groups 1-5 may include the ex-GWR railcars still in traffic, the ACV railcars, as well as early locomotives.