Sorry it took a few days, but I didn't forget. The total weight of the ready-to-fly nosecone assembly is 100g. There is no additional nose weight. Hope this helps!
I modified the nose cone shoulder similarly to the way you did, though not nearly as nicely finished. Finished nose cone weight is 186g, total rocket weight without a motor is 458g. That put the stability at 1.3 with the H motor I’m planning on using.
Three more flights on my Doorknob yesterday at MDRA's ESL 294. Two flights on E30-7s, and one on an F44-8. These are turning out to be wonderful motor options for this rocket. The wind was mostly blowing directly towards the nearest trees, so I also took the opportunity to try out my JLCR for the first time with the Doorknob. I had a slight shock cord tangle on the first try, but it still deployed the parachute just fine. The second chute release flight was totally nominal. I had a FlightSketch Mini on each flight to start getting some data from my flights to be able to validate the OpenRocket sims.
Flight 1: E30-7: 545"
Flight 2: E30-7: 531" (Used JLCR on this flight, which I think likely explains the slightly lower altitude?)
Flight 3: F44-8: 665"
Now with some practice using the chute release, I'm interested in trying an F67 in this rocket.