You could try here if you haven't already.
Part Listing Buymilsurp.com, Your source for military surplus. doesn't have any front sights.
Welcome to Numrich Gun Parts Corp. has some K98 and G98 front sights, but you'd have to contact them for their export rules.
Mauser Slip-On Band Style Front Sight Base*|*e-GunParts.com
This place has some front sights, but you'd have to call or contact them for further information as to the height of it whether or not it is taller than the one you have.
Ponderosa Enterprises
Hope that helps. Maybe you can get something. If you can't get anything, maybe some JB weld, or hitting the front sight with some weld material and filing it to fit the rest of the shape of the front sight? Or else file the bottom of the rear sight slide. bobvknob, a G&G member can figure out how much you'd need to take off the bottom to bring it back down at that distance with some measurements of how far apart your sights are and distance shooting. May be worthwhile to contact him as well.