Not mine madmostin, but one of the ones (along with Valter Ponzo's) that inspired me to make one. Great bike - better than standard 315 and easier to ride than 4RT in my humble opinion - and I own both. Will try and find photo of mine to post.
Will only work on later 315's with inboard rear disc. If earlier 315 you will need to use wheel and brake assy from 4RT as well.
Unless you mean you want to use a 315 arm to go in a 4RT in which case you will need an arm from a late 315 (inboard disc caliper type)
Hope that makes sense...
