Phew! Big day!
I decided to power through as much as I could (and my hand is doing surprisingly well).
So I've punched the extra 4 holes in all 200+ I had already punched with the incorrect spacing, and I've also punched about another 60 out of blanks. So I'm not only caught back up, but I've made some progress, sitting at 260/600.
Ultimately, I will most likely need to cut some more blanks (I have enough leather for probably 150 more) but with the changes I've made, I'm confident I can make this work. The whole thing will be about 4 inches shorter than I envisioned (ending about 3 inches below my waist line, as opposed to 3 inches above the knee, like the original) but I can add rows after the fact, in preparation for next year.
Chainmaille is on the way, my black shirt still sits at 95% complete, Leather is up to about 25% overall completion, need to order gloves.
Oh, and Vinegaroon is brewing. Should be ready by the time I have all 600 blanks cut. Then spend a day dying and treating the leather, and finally start lacing the whole thing together! Maybe two weeks from now and I should be seeing something near completion (Cutting more blanks, punching the holes, and dying will set me back, but I should have plenty of time for that. 5 weeks left, today!)