Oli that looks amazing, we need to see more of your collection!
There is a Mid on eBay now with that same chassis
http://www.ebay.com/itm/Kyosho-Optim...item4d06af1848
It makes me think that the couple times I thought I had seen a S/H OTW-5 on eBay maybe it was actually this chassis, though there was one ad with a close up that was clearly an OTW-5, eventually you will find one but I bet the Fibrelyte piece will be just fine