little bit of help please?

[gerbil]

Hi I've been rebuild my old kyosho optima mid and found that I have a striped diff gear
The part number is ot-85 I've seen them on ebay but only from the states has anyone got one in there boxes that I could tease away from them new or used just want to get it all back together with out waiting for postage from america
Anyhelp is greatly received
Also I've noticed a lot of lwb and swb chassis the car I have is a original kyosho optima mid the box has yellow outline and the car has the white bodyshell on the box if I wanted to buy a new chassis which one do I need lwb,swb oris there a option that's a normal one?
Once again any help is much appreciated thanks guys