The Auto Glym is new, a white bottle with a non glamorous little sticker on it that gives you the name. I'll see if I can find a link.
As for whether you have clear coat, if you have areas that are still shiny / glossy around edges or vertical panels then and the pieces that are horizontal have a whiter duller finish then you likely still have clear coat (this is a common faded clear coat from sunlight). If you have panels that are completely dull and have a rougher feel to them then you likely do not have clear coat.
A faded or damaged clear coat is still visible, a bit dull but not like a flat paint and usually has a white/milky tint to it.
Here found you a web site:
http://www.autoglym.co.uk/frame2.html
It is the Paint Renovator product, you can try the Super Resin Polish as well, I have not played with it but it should work fine. They have a lot of info on the site.
Found this one too:
http://www.noscratch.com/novus/
I am not sure if it is their official site but it gives you an idea.
Just remember both of these products are a cut polish, they will remove a very tiny amount of clear coat or paint so I would not recommend using these every time you wash your truck and just make sure to apply some good quality wax after to seal the finish in.