That's not surprising. Towards the end of the Mhz Wars the heatsinks had become pretty ungainly but they were still using the flimsy spring clip instead of the more modern 4 post or gantry type systems used today (sorry I'm sure they have proper names but damned if I know what they are).

I had a solid copper heatsink that was easily 5lbs for my Athlon XP system. I held onto it for the longest time after I got rid of the system because I knew the metal was easily worth $20.