A nice nod to the first published crossword puzzle. I read an article about the coming anniversary in Games Magazine, but I still could not remember without a few crosses, the constructor's name or the exact paper that published it. In my defense, even if the article had been in the December issue, to coincide with the month of publication (it wasn't, it was even longer ago), that issue probably showed up at our door back in August (we've had the March 2014 issue for a week or more), so it's been a while. I did, however, recognize the homage to the diamond shape of that first puzzle, but that didn't help much with the solve.
We bogged down up in the top middle, where SUMO (14D: Big sport overseas?) (!), NONPRO (6D: Hobbyist, e.g.), and SOLEMNER (14A: Less light) were slow to materialize. That last is very nicely clued, and it's a tricky word, but I think most people would probably say "more solemn" rather than "solemner," if they were going to use the comparative at all with that word, which, frankly, I don't think they would.
The "standard issue" OLES was given a nice clue today (26A: Acclaim for picadors), likewise ORO (28D: Cortés's quest). To use MAR as a noun, however, or "29D: Graffiti, say" as a verb, seems like a stretch. Is that what they're trying to do there? Neither use is supported by my deskside Random House College Dictionary, but it's not an unabridged, and it is Saturday, so go ahead, bend the definitions a bit, we can take it.
Liked the pairing of 21D: City on the Firth of Tay (DUNDEE) with the definition clue 60A: Firth, e.g. (INLET). The 3D: Noted geographical misnomer (GREENLAND) was nice, and we jumped the gun and put "amo" in for EST at 5D: Basic Latin verb. Never heard of TYES (18D: Sailors' chains) or DEWCLAW (23D: Canine vestigial structure), but both seemed plausible enough. The dew claw, by the way, is what is sometimes referred to as a "dog's thumb." It is a claw that sits higher up on the leg, and appears largely useless. Indeed, it is sometimes removed when the animal is young.
Lastly, we loved seeing LORELEI (37D: Rock singer?) because just last night we saw a Rick Steve's about Germany, wherein he went down the Rhine, and made special mention of the dangerous bend around the Lorelei.
A very nice Saturday, and, we think, a fitting tribute to the grid that launched a thousand blogs.
p.s. In the print version, the central diamond area is shaded gray, to commemorate the exact shape of the first puzzle. Further, the "FUN" in fungicide mirrors an exact answer in that first grid. Nice touches, I think.