Can anyone help me identify this Optimus?

I need help identifying this Optimus Prime I won on Ebay, It is almost in mint condition, no paint wear at all on the cab or anywhere else, only a little wear on the chromed parts, no rubsign indention, or any trace of where one was at all, at first I was like, oh this must be a ko but after I compared it to some pics of the ko I realized this was impossible as the paint apps on the ko are horrible and the ko does not have the ratcheting knees like this one does, furthermore to compound my confusion are the eyes on the robot head, they kind of come to a point where they meet up at the nose and the fists which obviously do not match this figure as they are a very tight fit. So what do you guys think? My thinking is: it is either a g1 original and I got lucky or it is a Japanese reissue. One more thing is the red on the cab is kinda light but is different from G2.
Also note I don't think this trailer came w/ him originally either as it is in nowhere near the condition of the cab, spots of dirt, rust, grease.
Here is a link to the auction: http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0294025179
Any assistance is appreciated.
Also note I don't think this trailer came w/ him originally either as it is in nowhere near the condition of the cab, spots of dirt, rust, grease.
Here is a link to the auction: http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0294025179
Any assistance is appreciated.