Sorry, after a lenghty investigation I was only able to find one photo, the one I reposted.
It's kinda hard to help with fit issues, without the option of actually laying hands on the parts... First question is did you already glue the parts? If yes then you have two options - fill and sand the gap or take them apart again. If you didn't glue the parts or you were able to take them apart again, then you have to look carefully for things like sprue attachment points not sanded proparly, or flash or similar casting artefacts. If these are taken care of, then you have to check if other parts are aligned properly and correct if necessary. In case of Tamiya models that should be enough. Try dry fitting the parts SEVERAL TIMES, that should give you the idea what's in the way of good fit, then you can take care of it by cutting off the ofending part or realigning everything properly.
By the way the photo I found shows some problems with alignment, of the towing hook attachment points for example - you might want to correct them soon, that will be easier than doing it later, or looking at them misaligned for years (I say that from experience!).
That's actually all I can tall you at this point, good luck with your build and have a nice day
Paweł