This was a pretty fun Monday. The revealer, COMETOPAPA (59A: Casino cry... or a hint for 16-, 23-, 37- and 45- Across) didn't really serve as a hint, since it was the last theme clue I solved, but I was on the right track after getting (with no crosses) PATPAULSEN (!) (16A: Comedian with a mock 1968 presidential campaign), and (with a few crosses) PARTPAYMENT (23A: Money that doesn't completely satisfy a debt).
It seemed a little tougher than Mondays sometimes are, with clues like 21A: Puff piece? (CIGAR), two uncommon proper names crossing in the South. And I thought ACTAS (24D: Represent) was a little tricky. I liked seeing "Fur ELISE" (62A: Beethoven dedicatee) in there, but I thought TWERP (7D: Insignificant punk) and LIKEICARE (34D: "Whatever!") were oddly EARTHY (43D: Coarse, as humor).
CRTS (9A: Old PC Monitors) confessed to being old-fashioned, but CYBER feels just as old these days, yet it claimed to be a 21D: Modern lead-in to cafe. I'm not sure I'd define 45D: Sang-froid as POISE, it seems more sinister, and I take mild offense at ARTY being defined as 5A: Pretentious. But perhaps Mr. Burnikel simply meant them as JESTS (47D: Remarks not to be taken seriously).
Lastly, although I think RLESS is pretty weak as fill, I let it pass today because of its fine clue - 50D: Like non-oyster months.