I have noticed that both Amazon and Ebay have very old Latin textbooks aimed at beginners and I was wondering if any of these would be worth purchasing.
I have three grammars, and three textbooks. I think they’ve each been useful in one way or another. Many of these old books can be found on Google–>Books. So you can examine them before purchasing one.
For me the grammar appendix in Moreland & Fleischer, Latin an Intensive Course, has been very useful. Its content is indexed most helpfully in the general index of the book.