I've got a Folksy front beam adjuster that I never got around to fitting, these were designed to fit the top tube only. It's as new with fitting instructions sheet, although that is a little battered having been in the bag with the adjustor for a number of years in my garage.
It's this one:-
https://books.google.co.uk/books?id=7xNbfr3_KgoC&pg=PA44&lpg=PA44&dq=folksy+beam+adjuster&source=bl&ots=sjy_KsHsWG&sig=cnoc1t4qdGixagBJ1hO0la4ZyVA&hl=en&sa=X&ved=0ahUKEwjcnb_lmp3cAhXRQ8AKHU9gAToQ6AEIVzAK#v=onepage&q&f=false
Cheers