http://www.toyota-supra.info/forums/...nd-7m-gte.html
You could also look to see if the turbo's oil drain runs to a location in the block near the block near the oil filter or if it's running to a bung placed in the oil pan. If its running to the oil pan and there's no return bung then it's not a GTE. The GTE also has an oil cooler setup for the engine and the GE doesn't... A lot of swaps leave this out. Just take the VIN to a dealership and ask for the info on the car's original equipment. Otherwise, the original registration info on file with the state will probably have it recorded.... OR get a Carfax report.
I've never heard of a factory GTE without the MA71 VIN (it's not like it's something they might run out of and have to switch over to the other)... but there's often some confusion over the chassis code punched into the frame in a couple places (such as the radiator support) which all say MA70. You can order replacement info tags, hood decals and glove box decals, so I wouldn't count on them as a reliable source. I *think* you can or used to be able to get replacement firewall tags from Toyota. That may be something only available to Toyota dealers. I knew of third party companies which deal with shops with accounts. I don't know if any of them will reproduce a tag with a VIN on it though.