Sad....but wherever there is money being spent...there will be scammers.
The more a bikes value goes up, the more likely you are to get people passing off junk as restored, or 'rare' examples cobbled together from the cheaper less sought after models. I mean...how hard would it be to pass off an F2 as an early K series. Swap a few bits...hide the rest with crud and rusty cast offs and call it a 'barn find'?