Replacement bolt and wing nut

I have used this router for many years. The threads on the wing nut and bolt, used to tighten the depth adjustment, have worn out. I can not find a replacement part to remedy this. Any suggestions?

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 0
crwdns2934285:0crwdne2934285:0