...finding them is like looking for a needle-head in a haystack.
The same could be said of finding a drop of a decent .com or a good any.tld name, that makes it under all of the radar screens and can be hand regged or picked up by one of the more passive, (and less expensive), backorder services.
Back in Jun, I ran across 195.us which was showing avail. on the open market. Couldn't reg it at the first two registrars I went to, who were showing it as unavail., but landed it at a third. Not a heavy hitter, but not bad for a hand reg, considering that by Jun, all 3LL and 3NN majors were in the backorder bracket.
Other than awkward, prefixed/suffixed adverbs, (ie unconstitutionally.com is avail.), or very obscure/archaic words, (often the second, uncommon spelling alternative), single word .coms aren't there.
Prompted by this thread, I pulled up the single word .coms that I had hand regged, (from my last attempt at mining them): knuckler.com, mineable.com (he-he), and unhistorical.com are my little string of,(gulp), "pearls".
Now that's a list that should cure anyone of spending too much time in pursuing the genre. But than again, others may have search techniques that are better than mine.