Yes, replacement mounting brackets can be purchased from Telect.
For 19" rack mounting the replacement brackets are:
06102B01+15 MTG BRKT LT 19" 1"TAB WITH UNIVERSAL MTG SLOTS,ROHS
06102B02+15 MTG BRKT RT 19" 1"TAB WITH UNIVERSAL MTG SLOTS,ROHS
For 23" rack mounting the replacement brackets are:
06102B03+15 MTG BRKT LT 19" 3"TAB WITH UNIVERSAL MTG SLOTS,ROHS
06102B04+15 MTG BRKT RT 19" 3"TAB WITH UNIVERSAL MTG SLOTS,ROHS