Dear Pepler: IMHO this could be an upgrade in better way than any LOMC and you don't have to breack the bank, please read it carefully:
http://forum.audiogon.com/cgi-bin/frr.pl?ranlg&1313624221&&&/Clearaudio-Virtuoso-Wood-Cartridge-
in the other side and with any cartridge you decide to go IMHO a change on tonearm over your modified RB250 could help a lot to improve quality performance.
Regards and enjoy the music,
raul.
http://forum.audiogon.com/cgi-bin/frr.pl?ranlg&1313624221&&&/Clearaudio-Virtuoso-Wood-Cartridge-
in the other side and with any cartridge you decide to go IMHO a change on tonearm over your modified RB250 could help a lot to improve quality performance.
Regards and enjoy the music,
raul.