Do not be fooled into believing that when it comes to the S range it is a case of "the lower the number, the poorer the pen". This is a long way from the truth, and there is no better model to test this theory on than the S.65

The S. 65 seems to have been one of those models that when introduced were a direct copy of the earlier H model with the same number. It then went through a series of revised designs, before ending production before WW2. The consistent design feature would appear to be the single, thin, cap band that appears on all the S.65 examples I have in my collection. 

S.65 black

I believe this to be the earliest s.65 design, coming with a 5 year warranty, and what is a rather small warranted 14ct nib. Note the 'unbreakable' logo central to the barrel stamp.

This early S.65 was also used as a basis for Lang on-brand production: here is an example of such a product the " CEE BEE" made for Coles the Sheffield department store:


Coloured marble examples were also available, again with the 'unbreakable' barrel stamp:


s65 barrel stamp

 I believe these were also used by Lang as the basis for the 'National Security' model made for British carbon Papers:

National Security

The above example would appear to be based upon the green S.65 further up the page, although the lever is of the more modern design that appears to have been introduced  into the S.65 range towards the end of its production:

s65 blue

This later design, which also included a change in barrel stamp (the removal of the unbreakable claim), was used for the Lang manufactured "Strand" brand.

strand pen