Five thematic clues are wordplay only, all of the others are normal (wordplay/def).
17d is thematic - a 'sugarloaf' is a type of headgear (3 letters) which goes around BE ['mountain' comes first, 3 letters].
25a First three words for the def - anag 'schism to' around R*
*You'll probably be wondering where the 'R' comes from (as did I, hankir). That's the thematic gimmick, and every clue features one (but a different word can give the same letter - and often does).
The 'R' in this case comes from a Londoner saying - 'alf a crown, which sounds like ''R for crown'' [so 'crown' is the special word in this clue].
Thanks ProfessorM.
This one will be difficult for people here to solve since East London argot is unknown.
I did figure out 10a where F is the letter for after. How that works, I don't know.
11d, the answer is obvious. But why leather becomes L was less clear until I thought 'ell for leather.
Yes, 'ell for leather - looks like you'll find this easier than you think, hankir.
And yes, there's an 'F' in 10a coming from what very loosely sounds like 'ever after' - ''F for after'' [there's a very old source for the theme (1940's) but some have been modernised - eg I think the Spice Girls feature in one of them].
I doubt if this will be easy, ProfessorM.
5D, the last letter could be C or X. But not sure how breakfst gets me there.
Man having beer before breakfast (4).
X = eggs (for breakfast).
18a SCRUM(p) is 'dwarf' - then 4 letters for 'wizard'.
38a 'chief of staff' = 'G for staff' - someone who scans the heavens follows.
ProfessorM, I have a few more including 18a.
Not sure how station becomes D in 12a.
or how sis becomes M in 6d
A few more like them. Is there a dictionary I can go to?
12a is 'a station' ('deforestation' = ''D for a station'').
6d 'emphasis' - ''M for sis''.
There's an old recording of the performance but it's a bit of a struggle to decipher what's being said and very few of the letters are repeated verbatim in the crossword, so I'd give it a miss (unless you're desperate}.
I haven't found a text as such, and this isn't anything like rhyming slang, so I just treated them as homophones (it helps if you can fake the accent}.