So about 10 to 12 years ago there was a book that was very popular in charity shops in the UK that I want to reread again. A summary of what I remember:
– This guy found(?) a load of art that was quite cryptic and had lots of pieces all with a number on (maybe in an old house/ attic)
– All the artwork fit together into one massive piece and this was a key discovery in the book (I think there were thousands of pieces and they all were numbered)
– It involved a children’s home/ orphanage; I think the painter was found to be painting out his childhood trauma
– Some of it was painted in blood (you found this out later)
– A policewoman was involved as the love interest and they slept together after her mum/ dad’s funeral
– I think it jumped between the present day and the past quite a lot with it all tying together in the end; i think the main character was the painter/ murderer’s sibling(?)
– The cover design was a lot like ‘the interpretation of murder’ (not sure if I can link here but the yellow-ish cover on google images)
– It may be quite a shit book as that is what I enjoyed reading at the time
Just a thought, but have you looked at the Richard & Judy book club lists? There’s an article listing them on Wikipedia.
My train of thought was that the yellowy cover of The Interpretation of Murder reminded me of Shadow of the Wind, which as far as I remember doesn’t sound like the book you’re describing, but I read it because of the Richard & Judy book club, which reminded me that those books sold massively but often ended up in charity shops. Good luck 🙂