Dan,
You can find these on these secondary market pretty easily. If you are going to York, they can be found there as well. I have 3 of them and will probably get a 4th if I find the one I'm looking for at York. All work great. The only thing that is a bit of a pain if loading the smoke fluid. It's much easier if you use a smoke fluid dispenser. I use the ones from JT's Mega-Steam. Here's what I'm referring to:
http://www.ebay.com/itm/like/292167925586
The tip of the dispenser fits into the tube much easier than the end of the tip on the smoke fluid which comes with the reefer. The tube connects the dispenser with the reservoir inside the reefer.
Regards,
Greg