Styrene - brittle plastic with a label that you could peel off: vinyl - more flexible and you could not remove the label however hard you try. Also, on certain records you'll find something called a delta number - this is a triangle symbol followed by a 5 or 6 digit number. It's a way of dating records. The higher the number, the newer the record, so your Illusions probably carries a number beginning 100** in the run off meaning it was pressed in 1977. Whereas an original Brenda Lee Jones on Rust would have a number beginning say 66***. The Barbara English one sided is a boot, as are The Ellusions, Del Larks, Tomangoes 99% probabability, Ann Perry if it's pale green.