I need your help people! PLZ!?

Ok, so when my mom was younger, my grandparents would get her Trixie Belden books for birthdays and Christmases. Eventually, she had the entire ORIGINAL collection. That means #1 through #34, since #35 through #39 were printed in a slightly different format. She kept her collection in very good condition and valued them her whole life. However, when I was younger, I loved to read these books. Unfortunately, I was highly irresponsible and eventually, through my carelessness, a lot of the books got torn up or ruined. Then later, when my brothers and sisters were bron and got older, they pretty much destroyed the rest of them. My mom told me that it wasn't a big deal and that they were just material possessions that didn't really matter, but I know it broke her heart to see her collection destroyed. Now, all these years later, I'd like to make it up to her. I know I can't bring back the love and memories she had in those books (each book had a meaningful inscription from my grandparents to her), but I'd at least like to make an effort to restore her collection to her. So now I finally come to my question. Does anyone know where I can find the original books, printed from 1948 to 1980? Numbers 1 through 34? Although it might be cool to be able to get her the other books, #35 - #39. I've looked on sites like amazon, ebay, abesbooks.com, and bookfever.com, but they mostly have the reprints they made in like 2004. I'm looking to find the original paperbacks. If anyone know where I can find them, I would greatly appreciate the help!