If I don't do it someone else will....
First a note on net etiquette:
Please turn your CAPS LOCK off. It's considered bad form to type in all caps -- people read it as though you're SHOUTING at them.
Also, maybe I'm just ignorant, or maybe English is not your first language but I don't know what you mean when you say "STEM" and "HARP." Could the HARP be the bridge? And the STEM the endpin?
Here's a bridge:
And an endpin:
Or maybe you were referring to the tailpiece:
In any event, I am not qualified to answer these questions but I think if you posted under the SETUP & REPAIR heading someone can help you out.