Short of time to give much explanation here, but the answers were pretty straight I thought. The only ones I had a problem with were SOURDOUGH (it is North American prospector) and I only think that SLUG is the answer to 27ac.
ACROSS
1 O-PINION (Eileen correctly informs me it’s not O-PEN-TOP)
5 LASAGNE
10 SA(I)D
11 HOT-TEN-TOTS
12 CEREAL
13 ABSTRACT
14 SOUR-DOUGH
16 LASS-O
17 CASTE
19 STAGEHAND
23 RATION-A-L
24 LIBIDO
26 CONVALESCE
27 SLUG
28 USURERS
29 CYGNETS
DOWN
2 PLACE-BO
3 NUD-GE : (E.G DUN) in reverse , where “dunning” is the process of chasing payment.
4 OT-HELLO
6 AVERS-E
7 AFTERMATH
8 NOTICES
9 STRAIGHT FLUSH
15 RETRIEVER
18 AT A LOSS
20 GALLERIES
21 NO DOUBT
22 ANG(L)ER
25 BA-SIN
1ac I had O,PINION!
26ac. CONVALESCE
27ac I had SLUG, too
7dn. AFTERMATH: I liked the [almost] &lit. here, as ‘aftermath’ originally meant a second crop.
See what happens when you are in a hurry … I’ll amend – thanks, Eileen.
Stan – I wasn’t arguing with your ‘open-top’! I think it works, too, as a cryptic clue
I thought it was case closed when I saw O-PEN = Nothing to restrict. I suppose “top” is a sort of view, but all in all it’s not as satisfying as O-PINION
I also had OPEN-TOP for 1 ac – but OPINION makes better sense. Interesting near-miss though.
I agree with SLUG for 27ac – it’s alive and it’s a kind of ammunition.
7dn AFTERMATH is interesting as one of those words that has changed its meaning to the opposite. As Eileen says, it orginally meant ‘a second mowing of grass from the same season’, but it now means ‘later consequences, esp. if bad’. Both quotes from Chambers.
I wasn’t sure about ‘Pure corn’ in the clue to 12ac CEREAL. Apparently it is used in making whiskey, as opposed to whisky.
Am I missing something? Isn’t it just cereal-serial. Where does the whisk(e)y come in?
Stan – do you mean GALLERY instead of GALLERIES for 20d?
SOURDOUGH came quite easily, but I had no end of bother with USURERS!
I went for OPENTOP for 1ac, though OPINION is nice. The word “There’s” at the start of the clue kind of made it feel more like a cryptic clue to me, for some reason… but either works.
12ac CEREAL, sounds like serial. But I couldn’t work out why PURE corn in the clue. Various links on Google say ‘pure corn’ is used in making whiskey (bourbon), as opposed to whisky (scotch). Maybe I’m reading too much into this?
I suspect “pure corn” was just to give a good surface reading.