Good to know. I just got a 517 that was converted into a DS80 and they actually went through the trouble to take apart the entire power switch and change that to a DS80 green switch, wheels, handle, nozzle, the works. Not by the seller - whoever owned it before the person I bought it from. It's been sitting in a basement likely 30, 40, 50 years. But it sure fooled me. It had all the correct attachments in the kit for the DS80, the manuals, I checked the photos carefully for things that didnt match and seen everything looked right.
But when I seen the OG 517 tag on the bottom I was like ????? That's when I had the thought that when people did that, their intention had to have been fraud, because that level of time and effort it took to do that and totally tear it down to rebuild it as a fake had to have taken a couple hours at least.