I have recently acquired this instrument, which is missing it's fret baffles and hence also missing the RH end label. After opening up to check the S/n, I noticed that the inner reed pan paper dials had been so cut as to remove the maker's name and address. I thought this was a bit strange, as other 're labelled' Lachenals which I have seen, still retain the full reed pan labels.
Also of note is the fact that there are valves fitted to all the highest notes, I had understood that this was incorrect, but have also noted it on quite a few similar instruments in the Concertina Museum collection?
What is the best source of info for Lachenal Serial number production dating, I have tried to date this but have been unable to find anything helpful on line (my internet search skills seem to be lacking!)
I include photos of the action and fret end to aid indentification/dating: