You'd have to know the full range of VIN's for your bike to know that. First VIN assigned to last. My FXR2 has the last 3 digits 431. Does that mean that mine was the 431st of the 901 produced ? or did the VIN's start at say, 350? Or 276, or whatever? 431st would be a reasonable guess, but only a guess unless the full range of assigned VIN's could be determined. And were the VIN's color specific? A range for each color starting with end of the first color? I personally doubt it, but again it's possible, I suppose. Another problem for me is that in 1999, the FXR2 and 3 were being produced. I would need to know if the frames were sequentially allotted to each bike, or mixed between the two?
For the FXR4, it was the sole FXR in 2000 so the frames should be uniquely VIN'd for that year. (one of the letters in the VIN denotes the year but I'd have to go look that up.) But then all the above questions still come up.