These ER sets would have one DMCL from diagram 559 and one from diagram 580 (the difference being one had a smoking first class section, the other was non-smoking), a TSL from diagram 583 and TBSL from diagram 584:
These are from the Derby Works Collection:
Single Engine Conversion
3-car diagrams & Works Pics
2-car diagrams & Drivers Instructions
4-car diagrams & Works Pics
Details about preserved Class 104s can be found here.
Many thanks to Kevin Dowd for his assistance in the preparation of these pages, and to Eddie Knorn for further data.