Local Crossword - Thank you in advance

[grahamr888]

1a) careless friends returning have a hurry (8) ?L???A??
17a) Pass American party speech on working together (13) ?O?L???R?L?S?
20a) Study hint about Germany and make inferences (8) ?O?C?R?E
23a) Give details of French writer (8) S?S?????
12d) Come back with a new cover (7) R?T?R?S

[fangster]

1a slapdash

[MarkRae]

1a SLAPDASH

[MarkRae]

17a COLLATERALISE (sorry!)

[Mamyalynne]

20 Concorde

[shoota]

20a Conclude

[Mamyalynne]

oops wrong letter - sorry

[shoota]

17a COL (hill) LAB (party) ORATES (speech)

[MarkRae]

12d I wonder if it might be RETREAD? The clue makes it unlikely that it will be either a plural noun or a third person singular present verb, so maybe the 'S' is incorrect?

[shoota]

Or rather Collaboration

[MarkRae]

Collaborates contains only 12 letters, though...

[MarkRae]

That's probably correct, shooty - difficult to tell...

[shoota]

So I found :-)

[grahamr888]

12d) Come back with a new cover (7)
Would now read R?B?R?S

[shoota]

12d Rebirth?

[Mamyalynne]

Like that Shoota

[grahamr888]

12d) Come back with a new cover (7)
Another change 12d) now read R?B?U??

[Mamyalynne]

Rebound as a book

[shoota]

Rebound

[shoota]

Has that altered 23a?

[MarkRae]

Blimey!