Bill, been busy, so did not see this thread. You could substitute K24's and K-53/701's (woofers and midranges) because in 1984 the remaining Heresy-I's had those instead of the K-22, K55/700 respectively. The tweeter, however, for all Heresy-I's was the K-77.
The K24's and K-53/701's (woofers and midranges) are available from Klipsch Parts. K-77's, however, are no longer available (not in that flavor anyways); you can always get a set of K-77 replacements from BEC (Bob Crites); his CT-125's are a drop in, direct replacement for the old K-77's and sound very good.
If you go that route, you will need to find a pair of E2 crossovers rather than E's. They are around. If all else fails, check with Bob Crites.
Hope that helps.