Dead regulator

I have not used my kegging equipment for over 6 years. So I have a couple questions...
I know my CO2 bottles are long past their test dates. Are they now useless or can I still exchange them?
I also remember that my gauges and or regulator leaked and I think replacing it would just be the best way to go. However I am seeing these CO2 cartridge keg chargers now that are way cheaper than big bottles and regulators. Are they just for dispensing or can they be used for force carbonation also?

I realize that these are newb questions but I am a re-beginner.

 

I would say as long as the cylinders were sealed and still held pressure they would be fine. If they've been sitting open and empty I'd say they'd probably have unwanted moisture or rust inside and I would just replace them. But if they are still pressurized I'd use the gas then have the cylinders hydro tested to be refilled.

As far as co2 cartridges I would think they would be primarily for dispensing. I would think it would take too many of them to carb a full keg. But not having tried I really couldn't say either way.

 

Well darn I just went out and checked the bottles and both of them have the valves wide open. I suppose that means they are probably toast inside. I might call around to the welding supply shops and see if I can get something for it.

 

You should be able to just trade them in.

 

The only time I had issues trying to trade one in was one past its hydro test date stamped on the cylinder. Otherwise I never had issues. To be honest most places that exchange don't check. That time they did. Guess I looked guilty or had a bad way about me lololololol.