Miller said it well
The pin that screws in the back is the bolt pin, or bolt guide. Same thing.
The only quest bolt that is not compatible with that pin is the 4b. But if you were to find one and buy one it would come with.
That said ill give you 75 for it right now
As far as problems to look out for I'd say read through the sticky. People have broken bolts which is prob what happened to the one you picked up. That usually only happens when your low pressure is set too high or there were a few defective gold bolts that were prone to braking.
The quests are really simple. But like miller said the wires can be a bit fragile at times. Take special care when disassembling the marker. The wires connecting at the solenoid also are known to fail if they get manhandled. Usually it's under shrink wrap where it breaks. If your noid won't click check the wires they could need soldering.