Across
Possibly time to finish messing about with our crossword, finally — staff should be locked up! (6,9)
I haven't cracked this one yet — but Fifteensquared have:
Anagram [messing about] of TO FINISH + OUR [crosswor]D round [should be locked up] MEN [staff] – a witty comment on the problems the Guardian crossword team occasionally have
Being amorous in the centre of Birmingham with Elvis? (7)
Modern sound then obvious, basic to the core? (7)
Field bound to be cut (3)
The man I saw's recollected? No! (11)
Inspector cunningly concealing university second degree in music (10)
I haven't cracked this one yet — but Fifteensquared have:
Anagram [cunningly] of INSPECTOR round U [university]
Inventor of the phone call? (4)
See 20
18a
Anything misbehaving types put on as a consequence? That's it! (3,7,4)
Spanner beginning to rotate, accessing both nuts in kitchen appliance (5,6)
I haven't cracked this one yet — but Fifteensquared have:
R[otate] in an anagram [nuts] of BOTH all inside FRIDGE [kitchen appliance] [This seems to have escaped from yesterday’s puzzle – but I thought the Editor didn’t allow that kind of thing?]
Intelligence lacking in underwear (3)
Delivery service longing for improvement (7)
A racket involving queen, say, backfiring — so stomach calmer? (7)
I haven't cracked this one yet — but Fifteensquared have:
A + a reversal [backfiring] of DIN [racket] round CAT [queen, say]
Old money is securing items of furniture — is one for an Italian friar? (7,2,6)
I haven't cracked this one yet — but Fifteensquared have:
FRANC IS [old money is] round SOFAS [items of furniture] + IS I [is one]
Down
Perhaps two left in a line among manual weapons (9)
I haven't cracked this one yet — but Fifteensquared have:
IN A L [in a line] in FISTS [manual weapons]
Release relative, not entirely a killer (7)
Mine triggered by this error message (8)
Philosophy of the puppy feeder? (5)
"Missing" unit — it's taken away, dashed? (5,4)
Sweet things in book collection most delightful (6)
Repeat, that is, about three times? (7)
I haven't cracked this one yet — but Fifteensquared have:
IE [that is] round T ERA T [three times!]
Conductor showing fortitude (5)
Diversity there on abandoned ship (9)
Giant in dispute with neighbour idly playing with alien (9)
Glass tubes broken up for starters, one of us getting knocked over (8)
Is a route across the Channel going north of a huge land mass? (7)
I haven't cracked this one yet — but Fifteensquared have:
IS A RUE [route across the Channel] reversed and before [going north of, in a down clue] A
Japanese cooker hot with vital energy, one degree higher (7)
I haven't cracked this one yet — but Fifteensquared have:
H [hot] + I BA [one degree] before [higher, in a down clue] CHI [vital energy]
Smart clothes are endlessly turning up for French politician (6)
I haven't cracked this one yet — but Fifteensquared have:
CHIC [smart] round [clothes – nice!] a reversal [turning up] of AR[e] endlessly
Slip down (5)
King getting wings clipped over female, very petite (5)
I haven't cracked this one yet — but Fifteensquared have:
[e]DWAR[d] [king] + F [female]
Type letters or click words in the clue