The documentary, Dildo Diaries, explores the topic in great, and sometimes hilarious detail. I happened to see this film around 2003, at a small art cinema, with Laura Barton and Judy Wilder present. So afterwards we had a Q&A. At that time one could sell/posses a 'representative model' for demonstrating how to put on a condom, but it was illegal if it also vibrated. And one could sell/ possess a non-anatomically correct 'dildo', which could legally vibrate. But one could not sell / purchase both from the same store. There were/ are literally stores that have an interior door dividing the two types. Also, if I recall correctly, there were limits on how many one could have, and categories including 'collectors' for those that had more than 6, I think.

https://www.imdb.com/title/tt0332604/plotsummary/?ref_=tt_ov_pl