Men's Gabriel D'Authie Blue and White Houndstooth Cardigan Sweater Size 3

Black and grey houndstooth pattern knit button front knit cardigan from a French brand called Gabriel D'Authie I'm not sure on the sizing, but it seems to me it will fit a men's M or a L, loosely. Vintage 90s or 80s. Measurements when laid flat (approximate) Bust: 20" Length: 26" Gently used condition. There's a small tear at one of the sleeves (photo 7). It's a simple fix that I don't trust myself to do! Other than that, no other major flaws Comes from a clean smoke free and pet free home