Thanks guys. As it's not much of a bike yet, my first thought was exactly like yours R.
However, my natural instinct is to follow Goldy, but I have hesitation about parting the flywheels as the set-up instructions in my manual are a little vague & I do not have micrometers or vee-blocks, etc.
I saw a guy in Israel selling a complete big end assembly on e-Bay for $80, but could not be sure about the part number he had, and it could be even worse than mine!