Yes, these AC safety capacitors are designed to open, instead of shorting. In the old days, they used standard paper capacitors in this application and those generally blew their guts all over the radio when they exploded. Given the fact that these old capacitors are 50+ years old and given the fact that there is a lot more garbage on the AC line than what there used to be, I'd strongly advise upgrading to the safety capacitors.
www.justradios.com has them, as well as a good write up on them. You can also get them from Mouser, and a number of other online vendors. On the Mouser site, I think they are listed as "AC noise suppression" capacitors. AC safety capacitors will have the "X" or "Y" designation on the capacitor. "X" is generally for "across the AC line" applications. "Y" capacitors are more suitable for connecting between one side of the AC line and the chassis.