I was cleaning out my boxes when I discovered @Beasmeeply not only sent me a primary mirror, but also a 46mm secondary mirror! Wow! Thank you!
Secondary mirror sizes are weird; apparently having a secondary mirror too small means the outer part of your view is slightly dimmer. I did lots of research into what kind of secondary mirror to use. This calculator says a 62.5mm will give me the most even illumination across the field, but that’s for super huge eyepieces so a slightly smaller one should be fine. I’d love to find a 60mm or 55mm one but I guess now I don’t have to look nearly as hard