I got two 30 LB propane tanks for $5 each and htey looked just like new because they had been inside an RV. The RV dealer just sold them new tanks. I tried to get the valve out on one with nothing but force and had no luck so thanks for yor explaination. I really appreciate it. I got the tanks for a gas forge too. I found Midwest Cylinder www.opdvalve.com 1-800-328-8902 You have to mail a check to them as they don't take credit cards. had the best price on OPD valves I could find. The 30 lb valves were $9.25 each and the 20 lb were $8.60 each.
Jon