All done. Nicely constructed and very interesting theme - thank you, Puffin.
Also an extraordinarily serendipitous theme for me - next Saturday I'm due to attend the celebration of the life of a recently deceased old friend whose career almost literally involved stepping in this pioneer's footsteps; and it's to be held at a highly thematic location - I will reveal all after the deadline date.
I'm still just a little antsy about the parsing of 6d - seems to me that the tense used in the wordplay of the clue yields the wrong extra letter. Or is it me that's wrong?
As to the title, it's quite obscure to me - the numerical bit doesn't correspond to either the historical or current thematic value - I don't expect any hints as these would almost certainly reveal too much