There is an excellent guide by Lamborghini_Race on buying classic Ping irons to which I would offer the following comments on lie adjustment:-
Almost all sellers mention that purchasers can have the lie angle adjusted by Ping free of charge. This may or may not be true. Ping Global say that there is zero lie adjustability in BeCu / Nickel heads and in some steel models; other steel heads have maximum lie adjustment of 2-4 degrees according to model.
Buyers beware, you can read all about it on the Ping website