John, If I understand you question correctly, you are not likely to suffer any liability here in the US.
False Marking: It appears to me that you are asking a question that would fall within the doctrine of False Marking. In the US, false marking occurs when marks an unpatented product as patented for the purpose of deceiving the public. 35 U.S.C. 292. The statute includes a fine of "not more than $500 for every such offense." A few yeas ago, there were a rash of false marking claims in the US for your very situation - expired patents. Those cases where somewhat successful and there were a couple hundred payouts in the $20,000-$200,000 range. In 2011, the false marking law changed as part of the America Invents Act (AIA). Under the new rule, the only parties that can bring a false-marking action are the US Gov't and someone who has suffered a competitive injury due to the false-marking. It is highly unlikely that either of these would occur in your situation.
Regarding previously marked products. The general operative is that the products are "marked" when you put them out in the stream of commerce and there is no need to conduct a recall to scrub patent numbers that expired after you sold the product.
Here is an article that provides slightly more information from a more international perspective.