Thank you, Chris of all tenses!
I'm wondering what was off with your original, 12 year old approach - it looks to me likeĀ "(maybe-not-bandlimited?)-saw-tooth-through-a-vcf" basically turned into "bandlimited-saw-tooth-or-sometimes-a-square-through-a-vcf." Doesn't look wildly different, but maybe the envelope and portmanteau had a big impact? Sounds pretty much like a 303 to my ears.
Future Brian, will you please send me some nice drums? You don't need to wait twelve years, I can start using them tonight...