Will go ahead and list differences I have noted in between the 1984, 1999, and 2001 contracts, all made by same J Adams...

1984 has much better finish in every respect, seems blade profile and primary edge done while metal hot, perhaps with rollers, more obtuse edge, rugged, but not the knife of later versions, but better wood wedge...have seen some 84 dated knives not near so nice, this one probably last of the breed of nicer ones, and finished more as earliest three versions (MOD 1-3) which were smaller, prettier, more hot-worked appearing knives.

1999 quite crude and pre-scratched, deeper flat grind, appears distal taper and depth of blade done while hot. Better chopper with deeper bite.

2001 shows no sign of hot work (to recollection), no distal taper or depth increase, less deep grind out front at tip (perhaps govt spec complaints or someone managed to damage a tip on the 1999, somehow).

Guards sharper edged on latter ones.

Even the blountest edged (but touched up) eldest knife still trims tough stringy small oak limbs with ease not found on far more expensive large knives, somehow, for some reason. I still scratch my head over that one.

All three work, the black dyed phenolic/micarta handle more comfy to my hand, as despite rougher slab cutting in spots, radii are better polished than wood. A very comfortable large, long handle on any of them, able to be held with only two fingers at hook for increased chopping power.

That about does it.