Thanks Hanno - I can only post these pics I have at hand and give a description as by the time I get home from work it it dark this time of year.
Left pic is C15A - number is between the 2 holes in F/L chassis rail and centred vertically.
Right pic is C60L - number is much lower and finishes around forward hole.
The pic I posted previously (with a lot of glare from my torch) is the Workshop C60L - the digits are smaller and start right next to the forward spring hanger.
Not a huge difference, but enough to throw this novice off, am sure the old hands are familiar with.
