Morning Henry,
I've just had a look at the Stanley site. By the look of it, this tool is a disposable unit as they don't show any parts charts. Also,given that Amazon sell this for under $30.00, I'd bite the bullet and get a new one?
Regards
Alex Bostitchtools co uk Bostitch Nailers Staplers Fasteners Coil Nails Staples
how old is this tool, if it is new take it back to where you bought it, most people try to repair them and get hurt in the process, if you have a repair center in your town take it to them and they will help you