'58 had the original small (Colt SAA size) XR3 grip frame so you'll need a vintage or custom set.....or SEE BELOW. Ruger changed to the larger XR3-RED (redesigned) in the '60's.
For a "close" fit you could try grips for one of the recently introduced small frame Vaqueros.
Of course there's eBay. THIS SET
will likely sell for a big hill of beans and is likely what your gun came with unless it letters as a W (walnut grips).