Harbor Freight will accept any of their older jack stands, made at any time, for a cash refund or store credit I believe. They have it on their website:
Harbor Freight buys their top quality tools from the same factories that supply our competitors. We cut out the middleman and pass the savings to you!
www.harborfreight.com
I took two pairs of jack stands in for return, even though they were not on the recall list. They gave me cash, no problem. What happened is that they issued the recall, and then some of the welds in the replacement jack stands were not up to standards. So, to try and gain back customer confidence, they just issued a broad edict that they will take back any HF jack stands. I have read online that some customers have had a hard time getting HF to honor the return policy, but it's right there on the website that it's at customer discretion (not store/manager discretion). I had no trouble at all.
So, if you have some older HF jack stands that you don't trust or just want to upgrade, take yours in and they should take care of you.