Theme:Don't Lose It - KEEPER can follow the first word of the entries.
18. Generic product : STORE BRAND. Like the mercantile retailer in an oater, STOREKEEPER.
26A. Xbox One, for one : GAME CONSOLE. GAMEKEEPER Perhaps there is one employed at Downton Abbey?
37A. Referee's call : "TIME OUT!". Then he may request the TIMEKEEPER put 3 more seconds on the clock.
47A. Image on many tie-dyed shirts : PEACE SYMBOL. Meanwhile, back at the oater, a different idea of a PEACE KEEPER.
62A. Angler's "I don't have to throw this one back," and hint to the first word of 18-, 26-, 37- and 47-Across : "IT'S A KEEPER". Say, do we have any anglers here?
Argyle here. I say this puzzle is a keeper.
Across:
1. Cabbage side : SLAW
5. Airplane maneuver : CLIMB. Can't hardly be called a plane if can't CLIMB, right Dudley?
10. Cookbook amts. : TSPs
14. Go it alone : SOLO. Also, airplane related.
15. Wild West movie : OATER
16. Peter Fonda's beekeeper : ULEE
17. Nursery school adhesive : GLUE
20. Southern Florida "trail" that's a portmanteau of the two cities it connects : TAMIAMI
22. Generating, as interest on an account : EARNING
23. Move covertly : SLINK
25. Bert's buddy : ERNIE. from Sesame Street.
30. Indiana hoopster : PACER. They are members of the Central Division in the Eastern Conference of the National Basketball Association.
31. Aegean island : IOS. But a search brings up iOS now; a phablet from Apple?
32. Computer input : DATA
36. Hold the title to : OWN
41. Young fellow : LAD
42. Barely makes, with "out" : EKES
44. Toyota __4: SUV model : RAV
45. Desert stopover : OASIS
51. Woodland deity : SATYR
54. Singer Lisa et al. : LOEBS
55. Readying a field, say : PLOWING
58. Fortified position : BASTION
64. Rooney of "60 Minutes" : ANDY. RIP
65. Sly look : LEER
66. Packed like sardines : IN OIL
67. Subject of adoration : ICON
68. Family chart : TREE
69. Group in pews : LAITY. Don't preach to the choir; preach to the laity.
70. Old-timey "not" : NARY. Nary a nit. Not likely.
Down:
1. NCO rank : SSGT. No mention a service branch can save a nit. (maybe)
2. Kinks girl who "walks like a woman and talks like a man" : LOLA
3. University grad : ALUM
4. Cry of distress : "WOE IS ME!"
5. Like some rays and dust : COSMIC
6. Spanglish speaker, often : LATINO
7. "Who am __ argue?" : I TO
8. Little more than : MERE
9. La __ Tar Pits : BREA
10. Show embarrassment : TURN RED
11. Done in, as a dragon : SLAIN
12. Old Finnish cent : PENNI
13. Marsh plant : SEDGE
19. Belgian composer Jacques : BREL. We've had him before but not often.
21. Make aware : ALERT
24. Evel on a bike : KNIEVEL. We've had him before but not often his last name.
26. Stare unsubtly : GAWK
27. Pimply condition : ACNE
28. U.S./Canada's __ Canals : SOO. Part of C.C.'s theme not too long ago.
29. Sch. whose mascot is Brutus Buckeye : OSU
30. "The Raven" poet : POE
33. Furthermore : ALSO
34. Wagger on the dog : TAIL. Cute.
35. Promos : ADS
38. 401(k) kin, briefly : IRA
39. Apple product : MAC. So is iOS.
40. Burial places : TOMBS
43. Surreptitious data-collecting computer program : SPYWARE
46. Choose not to vote : ABSTAIN
48. Estrada of "CHiPs" : ERIK
49. "Amen!" : "SO BE IT!"
50. Every September, say : YEARLY
51. Like milk on the floor : SPILT
52. Modify : ALTER
53. "We're off __ the wizard ..." : TO SEE
56. Playwright Simon : NEIL
57. Rowlands of "Gloria" : GENA. An old video of the song.
59. Ancient Andean : INCA
60. Fragrance : ODOR
61. Part of a B'way address : NY, NY. But truthfully, many places have a 'Broadway".
63. Hawaiian dish : POI
Argyle
