Odd Size Chanel 2.55 - Please help it's driving me mad!

Jun 11, 2015
I am in need of help please! I have a 2.55 Vintage 86-88 but I can't figure out the size. It's slightly larger than the medium but it's not a Jumbo. Is anyone aware of this size when they first made the 2.55?. It's 27cm X 17cm X 8cm. It's really driving me mad trying to figure it out.