Theme: Holy Holly- Double up the middle consonant to form the second word and clue appropriately.
20. Pilfered German fruit bread?: STOLEN STOLLEN
32. Evidence of Russia's currency collapse?: RUBLE RUBBLE
42. "Mister Ed" dot?: TITLE TITTLE
54. Final course in the Sahara?: DESERT DESSERT
Argyle here. No reveal Monday; not needed. Small nit; tittle is defined as a point or small sign used as a diacritical mark in writing or printing. MISTER ED doesn't use one; MR. ED does. Still fun.
Update: The dot on the lower-case "i" is also a tittle, at least according to some dictionaries.
Across:
1. Cartoonist Addams: "CHAS". Creator of The Addams Family.]
5. Sour substances: ACIDS
10. Parroted: APED
14. ___-poly: ROLY. May refer to: Link.
15. French painter of café scenes: MANET
16. Smallest American coin: DIME. Smallest in physical size.
17. Mil. no-show: AWOL. (Absence Without Leave)
18. "Fear of Flying" author Jong: ERICA. (1973 novel)
19. Herr's home: HAUS
23. Up until now: SO FAR
24. Timeline start: YEAR ONE
27. Play at the highest volume, as a radio: BLAST
31. Bravery award: MEDAL
37. Sch. in Charlottesville: UVA. (University of Virginia)
38. Words said with a nod: "I SEE"
39. Jeweled headpiece: TIARA
40. Stadium ticket designation: SEAT
41. Harbor puller: TUG
44. Bow and __: ARROW
46. Cotton thread: LISLE. A fine, high-twisted and hard-twisted cotton thread, at least two-ply, used for hosiery, gloves, etc.
47. Tortoni's cousin: SPUMONE
50. Pentathlon blades: EPEEs
58. B-movie safecracker: YEGG
60. Cheering noisily: AROAR
61. "Yes __?": ultimatum words: OR NO
62. Length times width: AREA
63. Infamous skater Harding: TONYA
64. Hall of Fame catcher Carlton: FISK. Nicknamed "Pudge" and "The Commander", Wiki Link.
65. Marries: WEDS
66. After-lunch sandwiches: OREOs
67. Lavish bash: FÊTE
Down:
1. Rude and crude: CRASS
2. Genre for do-it-yourselfers: HOW TO
3. Distant and cool: ALOOF
4. One of two in seven: SYLLABLE. The word, seven, is made up of two syllables.
5. Chorus from the pews: "AMEN"
6. Some "Wheel" prizes: CARS. You are better off on "The Price is Right" if you want a car.
7. "What's __ for me?": IN IT
8. Fake drake, say: DECOY
9. Opposite of fresh: STALE
10. Stick (to): ADHERE
11. Keyboard work for two: PIANO DUET
12. Rhea's Aussie relative: EMU
13. Hôtel __ Invalides: Paris landmark: DES
21. Author __ Stanley Gardner: ERLE. "Perry Mason"
22. Like a weak excuse: LAME
25. Part of USNA: NAVAL. (United States Naval Academy)
26. Make more than merry: ELATE
28. Intro-to-painting course: ART I
29. Exec's three-piece: SUIT
30. Little League precursor: T-BALL
32. Hayworth and Rudner: RITAs
33. Seize illegally: USURP
34. Gave reluctantly: BEGRUDGED
35. Matzo __: Jewish egg dish: BREI
36. Back muscles, in the gym: LATs. (lattismus dorsi)
40. Measures by pacing: STEPS OFF
42. Dance floor units: TWOs
43. Sights in la Méditerranée: ILEs. Here's a nice list of the îles de la mer Méditerranée to look over on those cold winter nights. List
45. Pricey watches: OMEGAs
48. "Gee, cool!": "NEATO!"
49. Mistake in the field: ERROR
51. Creepy: EERIE
52. Dadaist Max: ERNST. Road rage?
53. Tend to the flames: STOKE
55. Musical quality: TONE
56. Belafonte classic: DAY-O
57. Gaslight and Big Band: ERAs
58. Deviate from a course: YAW. (of a moving ship or aircraft) twist or oscillate about a vertical axis.
59. Before, in odes: ERE
Argyle