Which receiver did you end up going with that works with the servos? Or did you replace them as well?
ORIGINAL: poor judgement
personally... id forget all about any help from cen, or wrapping ur linkage, just replace the crappy rx man! i havent isolated any metal parts in the linkage at all, its not neccessary with a "real" radio in my experience - a new rx cost me £18, cured all my radio probs, and i just run it with no issues at all now in regards the radio.
a new rx is cheaper, quicker and less hassle than trying cens elusive bs radio exchange.