Hi,
I used the time over christmas to build a Lazer ZX out of mostly used but cleaned parts.
I have no intention on running it as I have a ZX-R MK 2 as a runner. So I call this ZX a "shelf-runner".
Next will be to build a ZX-RR also out of mostly used parts.
As for the ZX:
The Middle diff seems to be a real weak point. I think Kyosho at that time tried a bit to copy the system of the Siccom Magnum (also 3 diffs and a one-way to the front axis).
By the way:
I have listed some aftermarket parts for the old Lazer series:
http://www.oople.com/forums/showthread.php?t=60986
Cheers
Ralf