What's the Name of That Book??? discussion

Chatting to mum about forgotten books. She mentioned an old readers-digest book from when she was young. I am guessing maybe 60s-early 80s for when my gran was still getting the RD books.
The only thing she can give me to go on is the house was called Longbarrow.
Any help would be appreciated.

Possibly Mystery at Long Barrow House by Nancy Faulkner? Published originally in 1960, but WorldCat doesn't say whether it was released by RD.

Thank you so much - mum going to have a look at this and see if it jogs any memories. Not been able to find any second hand in UK which isn't extortionate.
Might need to see if can find a library copy.

It seems to be available on openlibrary.org; it appears that you have to create an account, but I don't know if there is a charge to do so.

Sent the link to mum now. Thanks again.

Good luck. Best regards to your mum.