I realized my initial photos didn't show the whole bush. I got pricked a few times, but I pulled out and moved enough of the grass and weeds so you can see the majority of the base of the plant. There are at least five living large stems (canes?) growing from the stump. There is at least one young one aside from those, as well.
Steve- tTanks so much for your info, I'll try the sulfur spray asap, I have to look online for some this afternoon. I'm also going to root some sprigs because only good can come from having more of this beauty in my garden. When all you find in store are scentless, it's amazing having the real thing right in your backyard.
fwmosher- Thank you for your analysis, I looked up photos of canker but I read that it turns white so I wasn't sure as I couldn't find any photos of examples that looked like mine. I hope I can save this old thing from death. It's survived worse, I'm sure.