Re: Seeking Forestay Release Lever
FYI, while I truly miss ABI, Hyfield levers aren't all that tough to either; make, or improvise. The latter for peanuts, plus the cost of a spare turnbuckle & a QR pin.
As in essence, the levers are simply camming mechanisms, with a long lever (mechanical advantage) on one part of the cam. You can find the plans for such levers & similar online, if you get stuck sketching out your own (design).
The Uncommon Thing, The Hard Thing, The Important Thing (in Life): Making Promises to Yourself, And Keeping Them.