i have been refurbishing a swinging arm, not much wrong with it, looks as good as new apart from a broken wheel adjuster stud in the hole on one side. so will not take long to drill that out until i look closer,its a broken tap not a stud, anyway after an hour or so i finally remove the tap, the hole had only been taped out 75% of the way through and broken off, conclusion the swinging arm has never been fitted, probably thrown where tom sopwith could not see it and probably had a harder time explaining the broken tap to the storeman ,but he was found out 100 years later
