It puzzles me that sawmills devalue tapped maple so much but when you try to buy some tap hole lumber it is priced way up above the same thing in other grades of lumber. It seems many like to make it into novelty items like wall switch covers and the like.
Good luck finding some. I might suggest you ask the New York State Maple Producers Association, they used it to panel their booth at the NYS Fair grounds.
Dave Klish, I recently ordered 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.