Stu (post above) has a good guide+video for replacing the ferro fluid. Did mine, fantastic improvement; for very minimal work. Emailed Seas this year; asking if the H1499 DXT was close to the H1054, Seas stated the H1212 was a better match (despite no waveguide). After rebuilding mine, the positive results curbed my interest in replacements, possibly a test of the SEAS Excel T25CF-001 if motivation returns.