Oh, in response to @NaughtyNoodler 's question about the role an agent possibly had in 'beefing up' the narrative and changing the title -- in TWS, SW says that the first thing that the commissioning editor at PRH says when they meet is 'We want to publish your book, but you'll have to change that title!'
So by her account, it's presumably still called Lightly Salted Blackberries at the point when it's bought by PRH, and was not changed by Jennifer Christie before being sent out. (Or so SW says. Which does not, of course, necessarily make it true...)
What role JC may have had in rewrites before the MS was sent out is impossible to know, other than that it's unlikely to have turned from a novel to a memoir under her guidance, as they're a non-fiction agency (though with some authors on the books who have gone on subsequently to write novels after signing with them for a non-fiction book or books.)
And I remember what I wanted to say about the varying weekly amounts of money, and varying accounts of whether or not they bought boot laces in Boscastle, and other variant anecdotes. I think it's evidence (if any were needed!) of the way in which SW's memory fails her repeatedly on the supposed detail of her own recent life, because she's not remembering things that actually happened, but the fictional use she made of something that possibly happened, but entirely differently.
One assumes they genuinely passed through Boscastle, and one of them possibly had a broken bootlace around then, but this occurs in a big 'focusing on our victimhood' bit of the book (soon after the Grant episode, in case we think it's all too easy), so in the same chapter there's the two of them hungrily watching two women eat a cream tea at 10.30 in the morning, the encounter with the unfriendly 'yompers' who describe the Walkers as 'blindly irresponsible', unfriendly, closed Boscastle etc.
Though I have always wondered, given that this is just after the bit where they discover they forgot to cancel their house insurance so have only £11 to live on for a week, how they expected to afford a pair of walking boot laces when they couldn't afford a bag of Boscastle chips? Laces are £5 or so as a minimum...?