I've shipped some heavy items packed by our local UPS Store and most have been fine with only one mishap. I was attracted to the idea that if an item is packed by them, then it is guaranteed by them. But lets say that the dustcover gets cracked. Will they reimburse you for the full price of the table? The problem being, it's really hard to find replacement parts for a lot of these vintage pieces.
The one item that I had damaged was the dust cover for a Akai GX-77 reel to reel, which would be near impossible to replace without replacing the entire unit. Turned out that the buyer was really cool about it and just glued it, so didn't want to pursue a claim, but I really don't think that they would have reimbursed for the entire unit.
I'm just glad that I rarely ever buy or sell anymore and that I don't have to worry about it as shipping, especially turntables, can be a real nightmare.