Consider selling (or keeping if funds permit) your new Handycam and shop around for a 1997/8 model. They are definitely out there and it's worth looking. Second-hand stores often have them and you see them advertised for sale. Now you know how to test for modifications you can perform them very quickly while examining the item as a prospective buyer.
I have heard of someone finding more than one unmodified 1998 Handycam for sale in the same shop but go to see the camera in person as the shop assistant may not know all its features and may even think it does not have nightshot when it does.
This is a drastic option but it is actually the best one if you only want to film infrared x-rays.
Sometimes, smaller stores have the old 1998 models on sale if they have stock left over, or you may find them advertised privately second-hand.