So I know this is a week old, but I just got around to getting the Bunny Day stuff myself. Just wanted to say thanks again for this! You did happen to miss the Earth Egg Shell Recipe though, it was 2A1.
I have a question though..do all of those items have recipes? Because 2A1 through 2C8 isn't enough. I'm missing recipes for the Basket, Vanity, Merry Balloons, Wall Clock, Glowy Garland, Stool and Bed. I'm going to try going further forward and backwards from the ranges you posted and see if anything else was missed. I'll post back if I find them. Otherwise, I'd appreciate the IDs if anyone has them.
Edit: Going backwards gave me normal items and forwards gave me blank cards. So either they strangely don't have recipes when everything else does..or the IDs are way more spaced out.