I'm looking for recommendations for an "old-fashioned" style of maths textbook for O-level/GCSE, i.e., one which is concise (not full of pictures) with plenty of exercises. Ideally something which is available in PDF format online. I don't necessarily mean an old book, more a book written in a style which is typical of the early 20th century or earlier. (For instance, Gwynne's Latin is a modern book for learning Latin which I would consider to fall under this category.)
I am quite fond of this one which I own a physical copy of, but am struggling to find anywhere online in PDF format.
Also I would appreciate if it is just one book rather than many volumes. A lot of maths textbooks made for school come in many volumes with titles like "School Maths 1A, 1B, 2A, 2B", etc.
To clarify, by "O-level/GCSE", I mean a book with a table of contents which should at least tackle all of the following:

I would recommend something like this. It's not specifically for O Level's or GCSE's but I've found it to be an excellent textbook.
Alternatively, if you are just looking for the facts and how to use the facts (so without any, or with very few proofs) then I can recommend the CGP GCSE Maths study guides. They are extremely cheap and extremely good, complete with plenty of examples and exercises.
You can also buy a CGP GCSE Maths questions book that is meant as a companion to the main study guide; it contains hundreds of questions, and is once more also very cheap. The links are below:
https://www.cgpbooks.co.uk/secondary-books/gcse/maths/mxhr47-new-2021-gcse-maths-edexcel-revision-guide
https://www.cgpbooks.co.uk/secondary-books/gcse/maths/mxhq42-gcse-maths-edexcel-exam-practice-workbook-h
They also have an option of an all-in one maths GCSE book, complete with practice as well:
https://www.cgpbooks.co.uk/secondary-books/gcse/maths/mxhs44-new-2021-gcse-maths-edexcel-complete-revisi
Personally, I would go for the book that is linked directly above, as well as the practice exam workbook as a bonus; thay are what I used (mainly the all in one book) for my GCSE Maths and they served me very well.