They shouldn’t be hard to find, our local bead company has them. Is
0.03" (0.762mm) or “long” a non-standard size?
Dentist suppliers have surgical steel wire in various diameters for
making braces. For the cheapest stainless steel wire, boating
suppliers or yacht chandlers have stainless steel cables which are
described as for example 24x0.7mm which means 24 strands of 0.7mm
wire; in a wide range of strand diameters. Buy a meter or yard of
suitable cable and unwind a strand as needed. This may or may not be
’surgical’ but is certainly stainless, is hard and springy, and the
downside - it unwinds in a spiral shape and has tiny decorative dents
evenly spaced along it.
Good luck, Alastair