Hi Colin

You've already sold HIE at about $50 per roll?..good on you! I have some HIE 35mm dated 1999 and some HIE 4x5 dated 1985 (all stored in the freezer), and no fogging, normal HIE grain. These are both beautiful films - esp the 35mm. I have some 16"x20" prints on Ilford MG FB from the 35mm (nudes photographed in the studio, around 1996).. the grain structure is well controlled, and actually look better than the 8"x10" prints!
I would say (as others have said here) use some of it and dev it yourself if you can - it is one of Kodak's great films.

Tony (from Oz)