In 1964, Bob Keane (founder of Del-Fi Records) started a label called Mustang, which recorded a band from Texas, the Bobby Fuller Four. Bobby Fuller was an admirer of Ritchie Valens and sought out Keane to record him when he moved to Los Angeles.
Fuller had a smash hit with ‘I Fought the Law’ for Mustang records before dying in a controversial suicide in July, 1966.
The Mustang label released 26 singles between November 1964 and March 1967.
Hold the record supported by 2 fingers from one hand through the spindle hole. Tap the edge of the disk with the other hand's index fingernail. If a ringing sound is produced the record is styrene; if the sound is a dull thud, it's vinyl.
NB. Use a fingertip, stick pen cap or similar object to support the record if it has the small (78/LP style) spindle hole.
If you live it..(meaning here), you learn these things........(so far you're the King of the Irish pressings to the UK pressings...the way I can spot the difference with a Canadian to a US pressing...you live it)...John
Almost every US Columbia/Epic/London after 1965 is on polystyrene..the label is glued on and sits atop a small shelf that's visible black wax..and as far as width of single they're very consistent one to the next (and they DO NOT BEND AT ALL/ no flexibility)...A US Vinyl single can run the gamut from almost brittle to very flexible and the label is pressed into the vinyl while it is being heat stamped , the label usually runs over the label "shelf" with a rounded curve edge...with the exception of a "Capitol" pressed single that has the gripper-ridges..in which case the label is (usually) cut smaller (you see gripper-ridges..you know it's vinyl!)....by the way US polystyrene singles get a bad rap...but if you have a mint one that has never been played with a bad stylus (and DJ copies usually have cue-burn..so be careful), they're usually cut loud and sound very good! )In fact I'll take a US Phillies or ABC/Dunhill on styrene any day..those labels used garbage on their vinyl pressings!...John