see my orders and payments but can't download itunes music

i see my complete order history, and all the music I purchased within the "order history" in iTunes, yet cannot download them nor do i see anyway to add them to "my playlist", and they don't show up in "my library". I am not exactly skilled ( an understatement) on using itunes,apple store etc., but i purchased the stuff ( it is all music..and all from the era before the mid 1980's last purchased in 2010) but would like to put in the library or playlist ( or both if possible) into the itunes application's folder so I can use/play it when i'm really, really bored..

Yes I'm old and clueless (-no ipod, no iPhone, no android..just a laptop computer and 3 towers that need minor repairs( like moving a jumper one place then back to restore the system,and on the other partitioning and installing linux to acess the hard drive again-the other is a pc running win 98..that one will not get plugged in as there is maybe 6gb of HD space and 2gbRAM-maybe -it was my first- and nothing important was ever on it) but are non-functioning at present..)

So if anyone can tell me how to retrieve the music i paid for and have the order history on , or what to contact to get some magic download again thing-y I'd like to know...thanks for reading this Best regards