ACROSS
 1 Hang on to a couple of bits to do this, and show no mercy. (4,2,7)
10 Put back the remainder with something from mine. (7)
11 In France he scatters coins about, to find some element of it. (7)
12 Hung around to find everything faded away around it. (7)
13 See 4 down
14 It makes a thing what it is. (7)
15 Point away behind, or in one direction? (7)
16 One’s 13 might be, or just listened to unofficially. (7)
20 A mechanical instrument, with crude oil, a pan being required for extraction. (7)
23 Making out in it might be expensive at some colleges. (7)
24 One arrangement of the tune let light in by it, perhaps like the moon. (7)
25 Last? Well, last with not quite everything! (7)
26 Perhaps a home away from home, with something you might give milk and water there. (7)
27 Does it demand dual personality to be so upset? (6,7)
 
DOWN
 2 Causes umbrage. (7)
 3 If plied onto me, I get feeling badly. (7)
 4 and 13 across What happens when the reporter misses a deadline might call for a reminder. (7,7)
 5 Some New Yorkers might consider capital where a vertical two-way switch might be. (7)
 6 Their husbands have gone, it’s clear, without a present to exchange. (7)
 7 Shut out. (7)
 8 Lucius to Horatius, or perhaps East
if one is West. (6,7)
 9 You’ll see it’s no tune, as an arrangement is made in a flash. (13)
17 Fade away, like a breeze led astray around it. (7)
18 Place where a minor accident ends with an oil spill, perhaps. (7)
19 What’s left after necessary deductions in a poor diet? One might eat there. (7)
20 One certainly has a large bill for food. (7)
21 Books of flowers? (7)
22 Nothing at breakfast, for example, might satisfy a Scotsman like this. (7)