Kitchen timers (Near Aston on Clun SY7)

Two darling little kitchen timers, the timer still works but the bell doesn't, so they're not much use as they are apart from decorative. Been hanging on to them as I love them both, and intended to 'fix' them (how hard can it be?!) BUT never got round to trying and have no idea how to fix the bell in them anyway. someone out there must be cleverer than I, surely? Repair shed/shop, anyone?