I remember in the 1970's we had a headmaster who thought that he could "reintroduce" it back into school but, unfortunately, it didn't go too well. After being use to writing with biros and then switching to "fountain pens" it was a struggle not to "cut through the paper" with the pen, as if one was producing a stencil. Eventually one would suffer a "broken nib" or worse a "split nib" but probably the worst catastrophe was a "ruptured ink sack", leaving one with a "lake of ink across one's exercise book".
With regards WW1 documents I do have some WW1 British"ration books/coupons" which are interesting because they date to WW1.