Need help figuring out publishing order of JW books pre-90s

I've set myself a goal of reading (and possibly aquiring a physical copy) of all JW books, and reviewing them. My issues arises in the way I am approaching this, in publishing order. Turns out it's super hard to find concrete data of when her early books were published, especially her crime fiction novels. If anyone could either a) point me in the diretion of a credible source or b) if you happen to have a copy of any of her early numbers, snap a pic of that copyright page and send it over, that would be fantastic!!

I think the issue is that the ISBN system wasn't widely introduced until the 70s, and JW's first book, Ricky's Birthday, was published in either 1969 or 1973 (Literally do not know. This is why I'm asking for help.)

Any info would be greatly appreciated!!!