Wow, that sure sounds like you got shafted. I'm not sure what I would do. my only suggestion is if you do get another guard it as well as you possibly can.
It might be a good time to try a Murphy cup and a good hydrometer, while you do need a larger sample, they seem to be fool proof and the cost for both is far less than $500.
I would think Misco would stand behind it, word like this getting out will sway lots of producers who were on the edge, between a Misco refractometer and the Murphy cup/hydrometer combo. This will hurt their future sales in my book.
Dave Klish, I recently bought a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.