I know a 600lb gun safe plus contents sounds like a lot of weight, and it is, but not extremely so to experienced professional safe movers,
This is so true, and an excellent point. As a mover on the side for perhaps a decade in my younger days, I did thousands of jobs. Dozens and dozens involving very heavy household things, and a handful were absolute beasts. Fridges and safes like the one you describe are kid stuff to move for people who know how. It's all technique and using every physical, mechanical and any other advantage at your disposal. This is particularly true if there aren't tons of stairs or tricky angles involved.
Anyway, I'm sorry for your loss, OP, and I hope you are properly compensated and the thieves caught. The heads-up is appreciated, too.
