If your getting a new matched kit, you should not have problems. If you are buying used parts, then buyer beware.... Also, the aluminum tanks are supposed to be pressure tested every five years.
The place re-filling the tanks are not supposed to fill an out of date tank. I don't know how much it costs to have the tank pressure tested. I used to pressure test gas cylinders as a summer job when in collage, but that was over 20 years ago...